Publications of Martin Fischer    :chronological  alphabetical  combined listing:

%% Papers Published   
@article{fds326162,
   Author = {Fischer, M},
   Title = {Shedding new light on old art},
   Journal = {Physics World},
   Volume = {26},
   Number = {12},
   Pages = {19-23},
   Year = {2013},
   Month = {December},
   url = {http://dx.doi.org/10.1088/2058-7058/26/12/30},
   Doi = {10.1088/2058-7058/26/12/30},
   Key = {fds326162}
}

@article{fds232529,
   Author = {Fischer, MC and Samineni, P and Li, B and Claytor, K and Warren,
             WS},
   Title = {Accessing nonlinear phase contrast in biological tissue
             using femtosecond laser pulse shaping},
   Journal = {Proceedings of SPIE},
   Volume = {8086},
   Number = {8086},
   Pages = {80860O},
   Year = {2011},
   ISSN = {1605-7422},
   url = {http://dx.doi.org/10.1117/12.889668},
   Abstract = {Nonlinear imaging takes advantage of the localized nature of
             the interaction to achieve high spatial resolution, optical
             sectioning, and deeper penetration in tissue. However,
             nonlinear contrast (other than fluorescence or harmonic
             generation) is generally difficult to measure because it is
             overwhelmed by the large background of detected illumination
             light. Especially challenging to measure is the nonlinear
             refractive index - accessing this quantity would allow the
             extension of widely employed phase microscopy methods to the
             nonlinear regime. We have developed a technique to suppress
             the background in these types of measurements by using
             femtosecond pulse shaping to encode nonlinear interactions
             in background-free regions of the frequency spectrum. Using
             this individual pulse shaping based technique we have been
             able to measure self-phase modulation (SPM) in highly
             scattering environments, such as biological tissue, with
             very modest power levels. Using our measurement technique we
             have demonstrated strong intrinsic SPM signatures of
             glutamate-induced neuronal activity in hippocampal brain
             slices. We have also extended this measurement method to
             cross-phase modulation, the two-color analogue to SPM. The
             two-color approach dramatically improves the measurement
             sensitivity by reducing undesired background and associated
             noise. We will describe the nonlinear phase contrast
             measurement technique and report on its application for
             imaging neuronal activity. © 2011 SPIE-OSA.},
   Doi = {10.1117/12.889668},
   Key = {fds232529}
}

@article{fds232530,
   Author = {Zhang, R and Greenberg, JA and Fischer, MC and Gauthier,
             DJ},
   Title = {Controllable ultrabroadband slow light in a warm rubidium
             vapor},
   Journal = {Journal of the Optical Society of America
             B},
   Volume = {28},
   Number = {11},
   Pages = {2578-2583},
   Year = {2011},
   ISSN = {0740-3224},
   url = {http://hdl.handle.net/10161/5105 Duke open
             access},
   Abstract = {We study ultrabroadband slow light in a warm rubidium vapor
             cell. By working between the D1 and D2 transitions, we find
             a several-nanometer window centered at 788:4nm in which the
             group index is highly uniform and the absorption is small
             (<1%). We demonstrate that we can control the group delay
             by varying the temperature of the cell, and we observe a
             tunable fractional delay of 18 for pulses as short as 250 fs
             (6:9nm bandwidth) with a fractional broadening of only 0.65
             and a power leakage of 55%. We find that a simple
             theoretical model is in excellent agreement with the
             experimental results. Using this model, we discuss the
             impact of the pulse's spectral characteristics on the
             distortion it incurs during propagation through the vapor.
             © 2011 Optical Society of America.},
   Doi = {10.1364/JOSAB.28.002578},
   Key = {fds232530}
}

@article{fds232531,
   Author = {Fischer, MC and Piletica, I and Fub, D and Matthewsa, TE and Liuc, H and Saminenia, P and Lid, B and Warrene, WS},
   Title = {Enhancing two-color absorption, self-phase modulation and
             raman microscopy signatures in tissue with femtosecond laser
             pulse shaping},
   Journal = {Proceedings of SPIE},
   Volume = {7183},
   Year = {2009},
   ISSN = {1605-7422},
   url = {http://dx.doi.org/10.1117/12.816488},
   Abstract = {Nonlinear microscopies (most commonly, two-photon
             fluorescence, second harmonic generation, and coherent
             anti-Stokes Raman scattering (CARS)) have had notable
             successes in imaging a variety of endogenous and exogenous
             targets in recent years. These methods generate light at a
             color different from any of the exciting laser pulses, which
             makes the signal relatively easy to detect. Our work has
             focused on developing microscopy techniques using a wider
             range of nonlinear signatures (two-photon absorption of
             nonfluorescent species, self phase modulation) which have
             some specific advantages - for example, in recent papers we
             have shown that we can differentiate between different types
             of melanin in pigmented lesions, image hemoglobin and its
             oxygenation, and measure neuronal activity. In general,
             these signatures do not generate light at a different color
             and we rely on the advantages of femtosecond laser pulse
             shaping methods to amplify the signals and make them visible
             (for example, using heterodyne detection of the induced
             signal with one of the co-propagating laser pulses). Here we
             extend this work to stimulated Raman and CARS geometries. In
             the simplest experiments, both colors arise from filtering a
             single fs laser pulse, then modulating afterwards; in other
             cases, we demonstrate that spectral reshaping can retain
             high frequency resolution in Raman and CARS geometries with
             femtosecond laser pulses. © 2009 SPIE.},
   Doi = {10.1117/12.816488},
   Key = {fds232531}
}

@article{fds232512,
   Author = {Warren, WS and Fischer, M and Fu, D and Ye, T and Piletic, I and Matthews,
             T},
   Title = {New nonlinear signatures in spectroscopy and
             imaging},
   Journal = {2008 Conference on Quantum Electronics and Laser Science
             Conference on Lasers and Electro-Optics,
             CLEO/QELS},
   Pages = {JWC1},
   Year = {2008},
   url = {http://dx.doi.org/10.1109/CLEO.2008.4552392},
   Abstract = {Ultrafast laser pulse shaping makes it possible to observe
             nonlinear signatures, such as self phase modulation and sum
             frequency absorption, at safe laser powers for tissue.
             Neuronal activation and melanoma diagnosis are two early
             targets. © 2008 Optical Society of America.},
   Doi = {10.1109/CLEO.2008.4552392},
   Key = {fds232512}
}

@article{fds232510,
   Author = {Fischer, MC and Liu, H and Piletic, IR and Ye, T and Yasuda, R and Warren,
             WS},
   Title = {Self-phase modulation and two-photon absorption imaging of
             cells and active neurons},
   Journal = {Proceedings of SPIE},
   Volume = {6442},
   Pages = {64421J},
   Booktitle = {Multiphoton Micr. in the Biomed. Sciences VII, Proc.
             SPIE},
   Year = {2007},
   ISSN = {1605-7422},
   url = {http://dx.doi.org/10.1117/12.698693},
   Abstract = {Even though multi-photon fluorescence microscopy offers
             higher resolution and better penetration depth than
             traditional fluorescence microscopy, its use is restricted
             to the detection of molecules that fluoresce. Two-photon
             absorption (TPA) imaging can provide contrast in
             non-fluorescent molecules while retaining the high
             resolution and sectioning capabilities of nonlinear imaging
             modalities. In the long-wavelength water window, tissue TPA
             is dominated by the endogenous molecules melanin and
             hemoglobin with an almost complete absence of endogenous
             two-photon fluorescence. A complementary nonlinear contrast
             mechanism is self-phase modulation (SPM), which can provide
             intrinsic signatures that can depend on local tissue
             anisotropy, chemical environment, or other structural
             properties. We have developed a spectral hole refilling
             measurement technique for TPA and SPM measurements using
             shaped ultrafast laser pulses. Here we report on a
             microscopy setup to simultaneously acquire 3D,
             high-resolution TPA and SPM images. We have acquired data in
             mounted B16 melanoma cells with very modest laser power
             levels. We will also discuss the possible application of
             this measurement technique to neuronal imaging. Since SPM is
             sensitive to material structure we can expect SPM properties
             of neurons to change during neuronal firing. Using our
             hole-refilling technique we have now demonstrated strong
             novel intrinsic nonlinear signatures of neuronal activation
             in a hippocampal brain slice. The observed changes in
             nonlinear signal upon collective activation were up to
             factors of two, unlike other intrinsic optical signal
             changes on the percent level. These results show that TPA
             and SPM imaging can provide important novel functional
             contrast in tissue using very modest power levels suitable
             for in vivo applications.},
   Doi = {10.1117/12.698693},
   Key = {fds232510}
}

@article{fds325990,
   Author = {Warren, WS and Miller, A and Ye, T and Liu, H and Fischer, MC and Wagner,
             W},
   Title = {Tissue imaging with shaped femtosecond laser
             pulses},
   Journal = {Springer Series in Chemical Physics},
   Volume = {88},
   Pages = {807-+},
   Booktitle = {Ultrafast Phenomena XV},
   Publisher = {Springer-Verlag},
   Year = {2007},
   ISBN = {978-3-540-68779-5},
   Abstract = {Rapid laser pulse shaping permit detection of novel
             molecular signatures such as self- and cross-phase
             modulation or nonlinear absorption. These effects are used
             to discriminate between different melanins in tissue and to
             monitor neuronal activation. © 2009 OSA/FiO/LS/AO/AIOM/COSI/LM/SRS
             2009.},
   Key = {fds325990}
}

@article{fds232508,
   Author = {Ye, T and Yurtsever, G and Fischer, M and Simon, JD and Warren,
             WS},
   Title = {Imaging melanin by two-photon absorption
             microscopy},
   Journal = {Proceedings of SPIE - The International Society for Optical
             Engineering},
   Volume = {6089},
   Pages = {60891X},
   Booktitle = {Multiphoton Micr. in the Biomed. Sciences VI, Proc.
             SPIE},
   Year = {2006},
   ISSN = {0277-786X},
   url = {http://dx.doi.org/10.1117/12.646139},
   Abstract = {Multiphoton excitation fluorescence microscopy has proven to
             be a powerful method for non-invasive, in vivo, thick tissue
             imaging with molecular specificity. However, many important
             endogenous biomolecules do not fluoresce (NAD) or fluoresce
             with low efficiency (Melanin). In this report femtosecond
             pulse shaping methods are used to measure two-photon
             absorption (TPA) directly with very high sensitivity.
             Combining with the laser scanning microscope, this
             Two-photon Absorption Microscopy (TPAM) retains the
             penetration and localization advantages of two-photon
             fluorescence microscopy and permits direct observation of
             important endogenous molecular markers (melanin or
             hemoglobin) which are invisible in multiphoton fluorescence
             microscopy. We have demonstrated here for the first time
             that TPAM can successfully and more efficiently image
             melanoma cells and tissues and provide a good melanin
             contrast in optical sectioning of the melanoma lesions which
             are comparable to pathological histology. Combining with the
             two-photon fluorescence images acquired simultaneously, the
             distribution patterns of the melanocytes and their
             intratissue behavior could be studied without cutting the
             lesions from patients. TPAM will undoubtedly find the
             applications in the clinical diagnosis and biomedical
             research.},
   Doi = {10.1117/12.646139},
   Key = {fds232508}
}

@article{fds232507,
   Author = {Fischer, MC and Ye, T and Yurtsever, G and Miller, A and Ciocca, M and Wagner, W and Warren, WS},
   Title = {Two-photon absorption and self-phase modulation measurements
             with shaped femtosecond laser pulses},
   Journal = {2005 Conference on Lasers and Electro-Optics,
             CLEO},
   Volume = {2},
   Pages = {968-970},
   Booktitle = {Proc. of the Conf. on Lasers and Electro-Optics},
   Year = {2005},
   Abstract = {We demonstrate experimentally that phase sensitive detection
             of spectral hole refilling can yield information about
             self-phase modulation and two-photon absorption
             coefficients. © 2005 Optical Society of
             America.},
   Key = {fds232507}
}

@article{fds232528,
   Author = {Ye, T and Fischer, M and Yurtsever, G and Warren,
             WS},
   Title = {Two-photon absorption microscopy of tissue},
   Journal = {2005 Conference on Lasers and Electro-Optics,
             CLEO},
   Volume = {2},
   Pages = {1512-1514},
   Booktitle = {Proc. of the Conf. on Lasers and Electro-Optics},
   Year = {2005},
   ISSN = {2162-2701},
   Abstract = {Two-photon absorption microscopy (TPAM) has been
             demonstrated to be able to image melanin with high
             sensitivity. TPAM opens up a wide range of nonfluorescent
             molecular targets. © 2005 Optical Society of
             America.},
   Key = {fds232528}
}

@article{fds232505,
   Author = {Ye, T and Wagner, W and Tian, P and Yurtsever, G and Fischer, M and Warren,
             WS},
   Title = {Deep tissue imaging approaches by direct capture of
             two-photon absorption},
   Journal = {2004 2nd IEEE International Symposium on Biomedical Imaging:
             Macro to Nano},
   Volume = {1},
   Pages = {668-671},
   Booktitle = {Proc. IEEE Int. Symp. on Biomed. Imag.},
   Year = {2004},
   Abstract = {Multiphoton imaging with fluorescence detection has proven
             to be a powerful method for moderately deep tissue imaging
             (less than 1 mm) with molecular specificity. However, many
             important endogenous biomolecules do not fluoresce (NAD) or
             with low efficiency (Melanin). In this paper two femtosecond
             pulse shaping methods have been demonstrated to detect
             two-photon absorption (TPA), instead of fluorescence, with
             high sensitivity, which opens up a wide range of molecular
             targets. It also facilitates longer excitation wavelengths,
             which permit greater tissue penetration. Developing the
             imaging system by using these new methods will be also
             discussed. © 2004 IEEE.},
   Key = {fds232505}
}

@article{fds232506,
   Author = {Warren, WS and Miller, A and Wagner, W and Ye, T and Fischer, M and Yurtsever, G},
   Title = {Two-photon absorption imaging with shaped femtosecond laser
             pulses},
   Journal = {Springer Series in Chemical Physics},
   Volume = {79},
   Pages = {867-869},
   Booktitle = {Ultrafast Phenomena XIV},
   Publisher = {Springer-Verlag},
   Year = {2004},
   ISSN = {0172-6218},
   Abstract = {Femtosecond laser pulse shaping permits background-free
             detection of two-photon absorption, which tends to refill
             spectral holes. This opens up new spectroscopic windows for
             monitoring tissue characteristics.},
   Key = {fds232506}
}

@article{fds53148,
   Author = {B. Gutiérrez-Medina and M. C. Fischer and M. G.
             Raizen},
   Title = {Observation of the quantum Zeno and anti-Zeno effects in an
             unstable system},
   Booktitle = {The Physics of Comm.: Proc. XXII Solvay Conf.
             Phys.},
   Publisher = {World Scientific},
   Editor = {Antoniou},
   Year = {2003},
   Key = {fds53148}
}


%% Preprints   
@article{fds325815,
   Author = {Warren, WS and Robles, F and Fischer, M and Wilson, J and Deb, S and Ju, K and Degan, S and Warren, WS and Robles, F and Fischer, M and Wilson, J and Deb,
             S and Ju, K and Degan, S},
   Title = {Melanin-targeted nonlinear microscopy for label-free
             molecular diagnosis and stagingMelanin-targeted nonlinear
             microscopy for label-free molecular diagnosis and
             staging},
   Journal = {Optics InfoBase Conference Papers},
   Volume = {Part F19-Translational 2016},
   Year = {2016},
   Month = {April},
   ISBN = {9781943580101},
   url = {http://dx.doi.org/10.1364/TRANSLATIONAL.2016.TTh3B.3},
   Abstract = {© OSA 2016. Nonlinear pump-probe microscopy differentiates
             cutaneous, vulvar and conjunctival melanomas from less
             dangerous lesions, and can be used to assess metastatic
             potential. Applications in vivo (knockout mouse models) and
             in human biopsy are presented.},
   Doi = {10.1364/TRANSLATIONAL.2016.TTh3B.3},
   Key = {fds325815}
}

@article{fds323186,
   Author = {Wilson, JW and Warren, WS and Fischer, MC},
   Title = {Real-time digital signal processing in multiphoton and
             time-resolved microscopy},
   Journal = {Proceedings of SPIE},
   Volume = {9703},
   Year = {2016},
   Month = {January},
   ISBN = {9781628419375},
   url = {http://dx.doi.org/10.1117/12.2218102},
   Abstract = {© 2016 SPIE. The use of multiphoton interactions in
             biological tissue for imaging contrast requires highly
             sensitive optical measurements. These often involve signal
             processing and filtering steps between the photodetector and
             the data acquisition device, such as photon counting and
             lock-in amplification. These steps can be implemented as
             real-time digital signal processing (DSP) elements on
             field-programmable gate array (FPGA) devices, an approach
             that affords much greater flexibility than commercial photon
             counting or lock-in devices. We will present progress toward
             developing two new FPGA-based DSP devices for multiphoton
             and time-resolved microscopy applications. The first is a
             high-speed multiharmonic lock-in amplifier for transient
             absorption microscopy, which is being developed for
             real-time analysis of the intensity-dependence of melanin,
             with applications in vivo and ex vivo (noninvasive
             histopathology of melanoma and pigmented lesions). The
             second device is a kHz lock-in amplifier running on a low
             cost ($50 - $200) development platform. It is our hope that
             these FPGA-based DSP devices will enable new, high-speed,
             low-cost applications in multiphoton and time-resolved
             microscopy.},
   Doi = {10.1117/12.2218102},
   Key = {fds323186}
}

@article{fds326161,
   Author = {Robles, FE and Fischer, MC and Warren, WS},
   Title = {Dispersion-based stimulated Raman scattering spectroscopy,
             holography, and optical coherence tomography (Conference
             Presentation)},
   Journal = {Proceedings of SPIE - The International Society for Optical
             Engineering},
   Volume = {9712},
   Year = {2016},
   url = {http://dx.doi.org/10.1117/12.2212875},
   Doi = {10.1117/12.2212875},
   Key = {fds326161}
}

@article{fds323187,
   Author = {Villafana, TE and Brown, W and Warren, WS and Fischer,
             M},
   Title = {Ultrafast pump-probe dynamics of iron oxide based earth
             pigments for applications to ancient pottery
             manufacture},
   Journal = {Proceedings of SPIE - The International Society for Optical
             Engineering},
   Volume = {9527},
   Year = {2015},
   Month = {January},
   ISBN = {9781628416879},
   url = {http://dx.doi.org/10.1117/12.2184758},
   Abstract = {© 2015 SPIE. We demonstrate that ultrafast pump-probe
             microscopy provides unique dynamics for natural iron oxide
             and iron hydroxide earth pigments, despite their chemical
             similarity. First, we conducted a pump-probe spectroscopy
             study on heat-treated hematite (the pure red iron oxide
             mineral) and found the pump-probe dynamics to be temperature
             dependent. Second, we investigated pottery fired under known
             conditions and observed firing dependent pump-probe
             dynamics. Finally, we imaged a New World potshard from the
             North Carolina Museum of Art. Our results indicate that
             pump-probe microscopy could be a useful tool in elucidating
             pottery manufacture.},
   Doi = {10.1117/12.2184758},
   Key = {fds323187}
}

@article{fds323188,
   Author = {Wilson, JW and Anderson, M and Park, JK and Fischer, MC and Warren,
             WS},
   Title = {Separating higher-order nonlinearities in transient
             absorption microscopy},
   Journal = {Proceedings of SPIE - The International Society for Optical
             Engineering},
   Volume = {9584},
   Year = {2015},
   Month = {January},
   ISBN = {9781628417500},
   url = {http://dx.doi.org/10.1117/12.2187133},
   Abstract = {© 2015 SPIE. The transient absorption response of melanin
             is a promising optically-accessible biomarker for
             distinguishing malignant melanoma from benign pigmented
             lesions, as demonstrated by earlier experiments on thin
             sections from biopsied tissue. The technique has also been
             demonstrated in vivo, but the higher optical intensity
             required for detecting these signals from backscattered
             light introduces higher-order nonlinearities in the
             transient response of melanin. These components that are
             higher than linear with respect to the pump or the probe
             introduce intensity-dependent changes to the overall
             response that complicate data analysis. However, our data
             also suggest these nonlinearities might be advantageous to
             in vivo imaging, in that different types of melanins have
             different nonlinear responses. Therefore, methods to
             separate linear from nonlinear components in transient
             absorption measurements might provide additional information
             to aid in the diagnosis of melanoma. We will discuss
             numerical methods for analyzing the various nonlinear
             contributions to pump-probe signals, with the ultimate
             objective of real time analysis using digital signal
             processing techniques. To that end, we have replaced the
             lock in amplifier in our pump-probe microscope with a
             high-speed data acquisition board, and reprogrammed the
             coprocessor field-programmable gate array (FPGA) to perform
             lock-in detection. The FPGA lock-in offers better
             performance than the commercial instrument, in terms of both
             signal to noise ratio and speed. In addition, the
             flexibility of the digital signal processing approach
             enables demodulation of more complicated waveforms, such as
             spread-spectrum sequences, which has the potential to
             accelerate microscopy methods that rely on slow relaxation
             phenomena, such as photothermal and phosphorescence lifetime
             imaging.},
   Doi = {10.1117/12.2187133},
   Key = {fds323188}
}

@article{fds232468,
   Author = {Park, JK and Fischer, MC and Susumu, K and Therien, MJ and Warren,
             WS},
   Title = {Femtosecond pulse train shaping for accurate two-photon
             excited fluorescence measurements},
   Journal = {Laser Science, LS 2014},
   Year = {2014},
   Month = {January},
   ISBN = {1557522863},
   Abstract = {We report a simple measurement method that exploits pulse
             train shaping to suppress linear contributions to the
             fluorescence, and allows for extraction of the two-photon
             absorption cross sections. © 2014 OSA.},
   Key = {fds232468}
}

@article{fds232469,
   Author = {Samineni, P and Fischer, MC and Liu, HC and Yasuda, R and Warren,
             WS},
   Title = {Nonlinear phase contrast imaging in neuronal
             tissue},
   Journal = {Optics InfoBase Conference Papers},
   Year = {2011},
   Month = {January},
   ISBN = {9781557529091},
   Abstract = {We demonstrate nonlinear phase contrast imaging in highly
             scattering media using rapid femtosecond pulse shaping of
             mode-locked laser pulses. We will also discuss potential
             applications of this technique for intrinsic functional
             neuronal imaging. © 2011 OSA: BODA/NTM/OMP/OTA.},
   Key = {fds232469}
}

@article{fds323189,
   Author = {Gutiérrez-Medina, B and Fischer, MC and Raizen,
             MG},
   Title = {Observation of the quantum zeno and anti-zeno effects in an
             unstable system},
   Journal = {Technical Digest - Summaries of Papers Presented at the
             Quantum Electronics and Laser Science Conference, QELS
             2001},
   Pages = {QPD1.1-QPD1.2},
   Year = {2001},
   Month = {January},
   ISBN = {155752663X},
   url = {http://dx.doi.org/10.1109/QELS.2001.962243},
   Abstract = {© 2001 Optical Soc. Of America. We study the motion of
             ultra-cold atoms in an accelerating optical lattice. We find
             that the tunneling dynamics are strongly affected by
             repeated measurement during the non-exponential time,
             leading to either inhibition (zeno) or enhancement
             (anti-zeno) of decay.},
   Doi = {10.1109/QELS.2001.962243},
   Key = {fds323189}
}


%% Journal Articles   
@article{fds328433,
   Author = {Wilson, JW and Robles, FE and Deb, S and Warren, WS and Fischer,
             MC},
   Title = {Comparison of pump-probe and hyperspectral imaging in
             unstained histology sections of pigmented
             lesions.},
   Journal = {Biomedical Optics Express},
   Volume = {8},
   Number = {8},
   Pages = {3882-3890},
   Year = {2017},
   Month = {August},
   url = {http://dx.doi.org/10.1364/boe.8.003882},
   Abstract = {Microscopic variations in melanin composition can be mapped
             through linear and nonlinear optical responses. Though
             instrumentation to measure linear attenuation is simple and
             inexpensive, the nonlinear response provides more degrees of
             freedom with which to spectroscopically resolve pigments.
             The objective of this study is to assess differences in
             imaging melanin contrast by comparing hyperspectral (linear)
             versus pump-probe (nonlinear) microscopy of unstained
             histology sections of pigmented lesions. The images and
             analysis we have presented here show that pump-probe
             uncovers a greater variation in pigment composition,
             compared with hyperspectral microscopy, and that the two
             methods yield complimentary biochemical information.},
   Doi = {10.1364/boe.8.003882},
   Key = {fds328433}
}

@article{fds325218,
   Author = {Robles, FE and Deb, S and Fischer, MC and Warren, WS and Selim,
             MA},
   Title = {Label-Free Imaging of Female Genital Tract Melanocytic
             Lesions With Pump-Probe Microscopy: A Promising Diagnostic
             Tool.},
   Journal = {Journal of Lower Genital Tract Disease},
   Volume = {21},
   Number = {2},
   Pages = {137-144},
   Year = {2017},
   Month = {April},
   url = {http://dx.doi.org/10.1097/lgt.0000000000000290},
   Abstract = {Melanomas of the female genital tract present a unique
             clinical challenge. Not only are these lesions in an
             anatomically sensitive area, but also they tend to be
             multifocal and have high recurrence rates. Furthermore,
             several benign melanocytic proliferations resemble
             early-stage melanoma clinically and/or histopathologically.
             Thus, there is a significant need for additional tools that
             can help correctly diagnose and stage these lesions. Here,
             we quantitatively and nondestructively analyze the chemical
             composition of melanin in excised pigmented lesions of the
             female genital tract using pump-probe microscopy, a
             high-resolution optical imaging technique that is sensitive
             to many biochemical properties of melanin.Thirty-one thin
             (~5 μm) tissue sections previously excised from female
             genital tract melanocytic lesions were imaged with
             pump-probe microscopy and analyzed.We find significant
             quantitative differences in melanin type and structure
             between melanoma and nonmalignant melanocytic
             proliferations. Our analysis also suggests a link between
             the molecular signatures of melanins and lesion-specific
             genetic mutations. Finally, significant differences are
             found between metastatic and nonmetastatic melanomas. The
             limitations of this work include the fact that molecular
             information is restricted to melanin pigment and the sample
             size is relatively small.Pump-probe microscopy provides
             unique information regarding the biochemical composition of
             genital tract melanocytic lesions, which can be used to
             improve the diagnosis and staging of vulvar
             melanomas.},
   Doi = {10.1097/lgt.0000000000000290},
   Key = {fds325218}
}

@article{fds325217,
   Author = {Robles, FE and Zhou, KC and Fischer, MC and Warren,
             WS},
   Title = {Stimulated Raman scattering spectroscopic optical coherence
             tomography},
   Journal = {Optica},
   Volume = {4},
   Number = {2},
   Pages = {243-243},
   Year = {2017},
   Month = {February},
   url = {http://dx.doi.org/10.1364/OPTICA.4.000243},
   Abstract = {© 2017 Optical Society of America.We integrate
             spectroscopic optical coherence tomography (SOCT) with
             stimulated Raman scattering (SRS) to enable simultaneously
             multiplexed spatial and spectral imaging with sensitivity to
             many endogenous biochemical species that play an important
             role in biology andmedicine. The combined approach, termed
             SRS-SOCT, overcomes the limitations of each individual
             method. Ultimately, SRS-SOCT has the potential to achieve
             fast, volumetric, and highly sensitive label-free molecular
             imaging. We demonstrate the approach by imaging excised
             human adipose tissue and detecting the lipids’ Raman
             signatures in the high-wavenumber region.},
   Doi = {10.1364/OPTICA.4.000243},
   Key = {fds325217}
}

@article{fds323184,
   Author = {Villafana, TE and Delaney, JK and Warren, WS and Fischer,
             MC},
   Title = {High-resolution, three-dimensional imaging of pigments and
             support in paper and textiles},
   Journal = {Journal of Cultural Heritage},
   Volume = {20},
   Pages = {583-588},
   Year = {2016},
   Month = {July},
   url = {http://dx.doi.org/10.1016/j.culher.2016.02.003},
   Doi = {10.1016/j.culher.2016.02.003},
   Key = {fds323184}
}

@article{fds323185,
   Author = {Fischer, MC and Wilson, JW and Robles, FE and Warren,
             WS},
   Title = {Invited Review Article: Pump-probe microscopy.},
   Journal = {Review of Scientific Instruments},
   Volume = {87},
   Number = {3},
   Pages = {031101},
   Year = {2016},
   Month = {March},
   url = {http://dx.doi.org/10.1063/1.4943211},
   Abstract = {Multiphoton microscopy has rapidly gained popularity in
             biomedical imaging and materials science because of its
             ability to provide three-dimensional images at high spatial
             and temporal resolution even in optically scattering
             environments. Currently the majority of commercial and
             home-built devices are based on two-photon fluorescence and
             harmonic generation contrast. These two contrast mechanisms
             are relatively easy to measure but can access only a limited
             range of endogenous targets. Recent developments in fast
             laser pulse generation, pulse shaping, and detection
             technology have made accessible a wide range of optical
             contrasts that utilize multiple pulses of different colors.
             Molecular excitation with multiple pulses offers a large
             number of adjustable parameters. For example, in two-pulse
             pump-probe microscopy, one can vary the wavelength of each
             excitation pulse, the detection wavelength, the timing
             between the excitation pulses, and the detection gating
             window after excitation. Such a large parameter space can
             provide much greater molecular specificity than existing
             single-color techniques and allow for structural and
             functional imaging without the need for exogenous dyes and
             labels, which might interfere with the system under study.
             In this review, we provide a tutorial overview, covering
             principles of pump-probe microscopy and experimental setup,
             challenges associated with signal detection and data
             processing, and an overview of applications.},
   Doi = {10.1063/1.4943211},
   Key = {fds323185}
}

@article{fds326160,
   Author = {Robles, FE and Fischer, MC and Warren, WS},
   Title = {Dispersion-based stimulated Raman scattering spectroscopy,
             holography, and optical coherence tomography.},
   Journal = {Optics express},
   Volume = {24},
   Number = {1},
   Pages = {485-498},
   Year = {2016},
   Month = {January},
   url = {http://dx.doi.org/10.1364/oe.24.000485},
   Abstract = {Stimulated Raman scattering (SRS) enables fast, high
             resolution imaging of chemical constituents important to
             biological structures and functional processes, both in a
             label-free manner and using exogenous biomarkers. While this
             technology has shown remarkable potential, it is currently
             limited to point scanning and can only probe a few Raman
             bands at a time (most often, only one). In this work we take
             a fundamentally different approach to detecting the small
             nonlinear signals based on dispersion effects that accompany
             the loss/gain processes in SRS. In this proof of concept, we
             demonstrate that the dispersive measurements are more robust
             to noise compared to amplitude-based measurements, which
             then permit spectral or spatial multiplexing (potentially
             both, simultaneously). Finally, we illustrate how this
             method may enable different strategies for biochemical
             imaging using phase microscopy and optical coherence
             tomography.},
   Doi = {10.1364/oe.24.000485},
   Key = {fds326160}
}

@article{fds232467,
   Author = {Wilson, JW and Park, JK and Warren, WS and Fischer,
             MC},
   Title = {Flexible digital signal processing architecture for
             narrowband and spread-spectrum lock-in detection in
             multiphoton microscopy and time-resolved
             spectroscopy.},
   Journal = {Review of Scientific Instruments},
   Volume = {86},
   Number = {3},
   Pages = {033707},
   Year = {2015},
   Month = {March},
   ISSN = {0034-6748},
   url = {http://dx.doi.org/10.1063/1.4916261},
   Abstract = {The lock-in amplifier is a critical component in many
             different types of experiments, because of its ability to
             reduce spurious or environmental noise components by
             restricting detection to a single frequency and phase. One
             example application is pump-probe microscopy, a multiphoton
             technique that leverages excited-state dynamics for imaging
             contrast. With this application in mind, we present here the
             design and implementation of a high-speed lock-in amplifier
             on the field-programmable gate array (FPGA) coprocessor of a
             data acquisition board. The most important advantage is the
             inherent ability to filter signals based on more complex
             modulation patterns. As an example, we use the flexibility
             of the FPGA approach to enable a novel pump-probe detection
             scheme based on spread-spectrum communications
             techniques.},
   Doi = {10.1063/1.4916261},
   Key = {fds232467}
}

@article{fds325989,
   Author = {Robles, FE and Deb, S and Wilson, JW and Gainey, CS and Selim, MA and Mosca, PJ and Tyler, DS and Fischer, MC and Warren,
             WS},
   Title = {Pump-probe imaging of pigmented cutaneous melanoma primary
             lesions gives insight into metastatic potential},
   Journal = {Biomedical Optics Express},
   Volume = {6},
   Number = {9},
   Pages = {3631-3645},
   Year = {2015},
   Month = {January},
   url = {http://dx.doi.org/10.1364/BOE.6.00363},
   Abstract = {© 2015 Optical Society of America. Metastatic melanoma is
             associated with a poor prognosis, but no method reliably
             predicts which melanomas of a given stage will ultimately
             metastasize and which will not. While sentinel lymph node
             biopsy (SLNB) has emerged as the most powerful predictor of
             metastatic disease, the majority of people dying from
             metastatic melanoma still have a negative SLNB. Here we
             analyze pump-probe microscopy images of thin biopsy slides
             of primary melanomas to assess their metastatic potential.
             Pumpprobe microscopy reveals detailed chemical information
             of melanin with subcellular spatial resolution.
             Quantification of the molecular signatures without reference
             standards is achieved using a geometrical representation of
             principal component analysis. Melanin structure is analyzed
             in unison with the chemical information by applying
             principles of mathematical morphology. Results show that
             melanin in metastatic primary lesions ha s lower chemical
             diversity than non-metastatic primary lesions, and contains
             two distinct phenotypes that are indicative of aggressive
             disease. Further, the mathematical morphology analysis
             reveals melanin in metastatic primary lesions has a distinct
             “dusty” quality. Finally, a statistical analysis shows
             that the combination of the chemical information with
             spatial structures predicts metastatic potential with much
             better sensitivity than SLNB and high specificity,
             suggesting pump-probe microscopy can be an important tool to
             help predict the metastatic potential of
             melanomas.},
   Doi = {10.1364/BOE.6.00363},
   Key = {fds325989}
}

@article{fds232470,
   Author = {Park, JK and Fischer, MC and Susumu, K and Therien, MJ and Warren,
             WS},
   Title = {Femtosecond pulse train shaping improves two-photon excited
             fluorescence measurements.},
   Journal = {Optics Letters},
   Volume = {39},
   Number = {19},
   Pages = {5606-5609},
   Year = {2014},
   Month = {October},
   ISSN = {0146-9592},
   url = {http://dx.doi.org/10.1364/ol.39.005606},
   Abstract = {Measurements of two-photon absorption (TPA) cross sections
             are greatly confounded by even very weak linear absorption,
             for example from hot bands. In this case, the experimental
             power dependence of fluorescence from amplified and
             mode-locked laser systems can differ drastically, even if
             the peak intensity is adjusted to be the same in both cases.
             A simple pulse train shaping method suppresses linear
             contributions and extracts the nonlinear absorption cross
             section, demonstrated here for a meso-to-meso ethyne-bridged
             bis[(porphinato)zinc(II)] fluorophore (DD) at 800 nm. This
             approach permits reliable TPA cross-section measurement,
             even with standard modelocked lasers under conditions
             identical to that used for multiphoton microscopy.},
   Doi = {10.1364/ol.39.005606},
   Key = {fds232470}
}

@article{fds232471,
   Author = {Robles, FE and Fischer, MC and Warren, WS},
   Title = {Femtosecond pulse shaping enables detection of optical
             Kerr-effect (OKE) dynamics for molecular
             imaging.},
   Journal = {Optics Letters},
   Volume = {39},
   Number = {16},
   Pages = {4788-4791},
   Year = {2014},
   Month = {August},
   ISSN = {0146-9592},
   url = {http://dx.doi.org/10.1364/ol.39.004788},
   Abstract = {We apply femtosecond pulse shaping to generate optical pulse
             trains that directly access a material's nonlinear
             refractive index (n2) and can thus determine time-resolved
             optical Kerr-effect (OKE) dynamics. Two types of static
             pulse trains are discussed: The first uses two identical
             fields delayed in time, plus a pump field at a different
             wavelength. Time-resolved OKE dynamics are retrieved by
             monitoring the phase of the interference pattern produced by
             the two identical fields in the Fourier-domain (FD) as a
             function of pump-probe-time-delay (where the probe is one of
             the two identical fields). The second pulse train uses three
             fields with equal time delays, but with the center field
             phase shifted by π/2. In this pulse scheme, changes on a
             sample's nonlinear refractive index produce a new frequency
             in the FD signal, which in turn yields background-free
             intensity changes in the conjugate (time) domain and
             provides superior signal-to-noise ratios. The demonstrated
             sensitivity improvements enable, for the first time to our
             knowledge, molecular imaging based on OKE
             dynamics.},
   Doi = {10.1364/ol.39.004788},
   Key = {fds232471}
}

@article{fds232493,
   Author = {Villafana, TE and Brown, WP and Delaney, JK and Palmer, M and Warren,
             WS and Fischer, MC},
   Title = {Femtosecond pump-probe microscopy generates virtual
             cross-sections in historic artwork.},
   Journal = {Proceedings of the National Academy of Sciences of
             USA},
   Volume = {111},
   Number = {5},
   Pages = {1708-1713},
   Year = {2014},
   Month = {February},
   ISSN = {0027-8424},
   url = {http://dx.doi.org/10.1073/pnas.1317230111},
   Abstract = {The layering structure of a painting contains a wealth of
             information about the artist's choice of materials and
             working methods, but currently, no 3D noninvasive method
             exists to replace the taking of small paint samples in the
             study of the stratigraphy. Here, we adapt femtosecond
             pump-probe imaging, previously shown in tissue, to the case
             of the color palette in paintings, where chromophores have
             much greater variety. We show that combining the contrasts
             of multispectral and multidelay pump-probe spectroscopy
             permits nondestructive 3D imaging of paintings with
             molecular and structural contrast, even for pigments with
             linear absorption spectra that are broad and relatively
             featureless. We show virtual cross-sectioning capabilities
             in mockup paintings, with pigment separation and
             nondestructive imaging on an intact 14th century painting
             (The crucifixion by Puccio Capanna). Our approach makes it
             possible to extract microscopic information for a broad
             range of applications to cultural heritage.},
   Doi = {10.1073/pnas.1317230111},
   Key = {fds232493}
}

@article{fds323578,
   Author = {Wilson, JW and Degan, S and Warren, WS and Fischer,
             MC},
   Title = {Optical clearing of archive-compatible paraffin embedded
             tissue for multiphoton microscopy (vol 3, pg 2752,
             2012)},
   Journal = {Biomedical Optics Express},
   Volume = {4},
   Number = {2},
   Pages = {219-219},
   Year = {2013},
   Month = {February},
   url = {http://dx.doi.org/10.1364/BOE.4.000219},
   Doi = {10.1364/BOE.4.000219},
   Key = {fds323578}
}

@article{fds232498,
   Author = {Wilson, JW and Degan, S and Fischer, MC and Warren,
             WS},
   Title = {Optical clearing and multiphoton imaging of
             paraffin-embedded specimens},
   Journal = {Proceedings of SPIE},
   Volume = {8588},
   Year = {2013},
   ISSN = {1605-7422},
   url = {http://dx.doi.org/10.1117/12.2003155},
   Abstract = {New labeling, imaging, or analysis tools could provide new
             retrospective insights when applied to archived,
             paraffinembedded samples. Deep-tissue multiphoton microscopy
             of paraffin-embedded specimens is achieved using optical
             clearing with mineral oil. We tested a variety of murine
             tissue specimens including skin, lung, spleen, kidney, and
             heart, acquiring multiphoton autofluorescence and
             second-harmonic generation, and pump-probe images This
             technique introduces the capability for non-destructive
             3-dimensional microscopic imaging of existing archived
             pathology specimens, enabling retrospective studies. © 2013
             SPIE.},
   Doi = {10.1117/12.2003155},
   Key = {fds232498}
}

@article{fds232499,
   Author = {Robles, FE and Wilson, JW and Fischer, MC and Warren,
             WS},
   Title = {Adapting phasor analysis for nonlinear pump-probe
             microscopy},
   Journal = {Proceedings of SPIE},
   Volume = {8589},
   Year = {2013},
   ISSN = {1605-7422},
   url = {http://dx.doi.org/10.1117/12.2002600},
   Abstract = {Phasor analysis has become a powerful tool for examining
             signals in fluorescence life-time microscopy (FLIM), where
             the analysis provides a fast, robust and intuitive means of
             separating different fluorescent species and mixtures
             thereof. In this work we adapt this analysis for pump-probe
             microscopy, a method that provides molecular contrast of
             pigmented samples by probing their excited state dynamic
             properties. The bipolar nature of the pump-probe signals
             presents important differences in the resulting phasors
             compared to FLIM - here, we discuss these differences and
             describe the behavior of bipolar signals in phasor analysis.
             Results show that this method is indeed able to separate
             multiple molecular species of interests and allows facile
             assessment of pigment chemistry and its distribution in
             samples. © 2013 Copyright SPIE.},
   Doi = {10.1117/12.2002600},
   Key = {fds232499}
}

@article{fds232491,
   Author = {Villafaña, TE and Samineni, P and Warren, WS and Fischer,
             MC},
   Title = {Historical pigments revealed by pump-probe
             microscopy},
   Journal = {Laser Science, LS 2012},
   Year = {2012},
   Month = {December},
   Abstract = {Nonlinear optical pump-probe microscopy is able to
             sensitively extract excited state dynamics from historical
             art pigments. This technique allows three-dimensional
             imaging and characterization of different pigments, with far
             reaching applications for conservation science. © OSA
             2012.},
   Key = {fds232491}
}

@article{fds232492,
   Author = {Wilson, JW and Samineni, P and Fischer, MC and Warren,
             WS},
   Title = {Nonlinear cross-phase modulation microscopy using spectral
             shifting},
   Journal = {Optics InfoBase Conference Papers},
   Year = {2012},
   Month = {December},
   Abstract = {Nonlinear phase contrast may be acquired by measuring
             spectral shifting of an ultrafast pulse due to cross phase
             modulation. This technique is used to obtain structural
             details in a pigmented cell from a melanoma biopsy. © OSA
             2012.},
   Key = {fds232492}
}

@article{fds232494,
   Author = {Samineni, P and DeCruz, A and Villafana, T and Fischer, MC and Warren,
             WS},
   Title = {Pump-probe microscopy of pigments used in historical
             art},
   Journal = {CLEO: Science and Innovations, CLEO_SI 2012},
   Pages = {CF1B.1},
   Year = {2012},
   Month = {December},
   Abstract = {We have developed a nonlinear microscopy technique that uses
             sensitive modulation transfer to extract excited state
             dynamics with high spatial resolution. Here, we use this
             technique to characterize several pigments used in
             historical artwork. © OSA 2012.},
   Key = {fds232494}
}

@article{fds232495,
   Author = {Wilson, JW and Samineni, P and Fischer, MC and Warren,
             WS},
   Title = {Nonlinear cross-phase modulation microscopy using spectral
             shifting},
   Journal = {CLEO: Science and Innovations, CLEO_SI 2012},
   Pages = {JW3G.2},
   Year = {2012},
   Month = {December},
   Abstract = {Nonlinear phase contrast may be acquired by measuring
             spectral shifting of an ultrafast pulse due to cross phase
             modulation. This technique is used to obtain structural
             details in a pigmented cell from a melanoma biopsy. © OSA
             2012.},
   Key = {fds232495}
}

@article{fds232496,
   Author = {Li, B and Yi, C and Brown, A and Fischer, MC and Warren,
             WS},
   Title = {Homodyne near-degenerate four-wave-mixing microscopy for
             graphene imaging and biomedical applications},
   Journal = {CLEO: Science and Innovations, CLEO_SI 2012},
   Pages = {CF1B.3},
   Year = {2012},
   Month = {December},
   Abstract = {Homodyne detection of near-degenerate four-wave-mixing with
             a single laser pulse is used to imaging graphene in
             biological samples. © OSA 2012.},
   Key = {fds232496}
}

@article{fds232497,
   Author = {Wilson, JW and Samineni, P and Fischer, MC and Warren,
             WS},
   Title = {Nonlinear cross-phase modulation microscopy using spectral
             shifting},
   Journal = {CLEO: Applications and Technology, CLEO_AT
             2012},
   Pages = {JW3G.2},
   Year = {2012},
   Month = {December},
   Abstract = {Nonlinear phase contrast may be acquired by measuring
             spectral shifting of an ultrafast ulse due to cross phase
             modulation. This technique is used to obtain structural
             details in a pigmented cell from a melanoma biopsy. © OSA
             2012.},
   Key = {fds232497}
}

@article{fds232526,
   Author = {Li, B and Cheng, Y and Liu, J and Yi, C and Brown, AS and Yuan, H and Vo-Dinh,
             T and Fischer, MC and Warren, WS},
   Title = {Direct optical imaging of graphene in vitro by nonlinear
             femtosecond laser spectral reshaping.},
   Journal = {Nano Letters},
   Volume = {12},
   Number = {11},
   Pages = {5936-5940},
   Year = {2012},
   Month = {November},
   url = {http://www.ncbi.nlm.nih.gov/pubmed/23101475},
   Abstract = {Nonlinear optical microscopy, based on femtosecond laser
             spectral reshaping, characterized and imaged graphene
             samples made from different methods, both on slides and in a
             biological environment. This technique clearly discriminates
             between graphene flakes with different numbers of layers and
             reveals the distinct nonlinear optical properties of reduced
             graphene oxide as compared to mechanically exfoliated or
             chemical vapor deposition grown graphene. The nonlinearity
             makes it applicable to scattering samples (such as tissue)
             as opposed to previous methods, such as transmission. This
             was demonstrated by high-resolution imaging of breast cancer
             cells incubated with graphene flakes.},
   Doi = {10.1021/nl303358p},
   Key = {fds232526}
}

@article{fds232523,
   Author = {Wilson, JW and Degan, S and Warren, WS and Fischer,
             MC},
   Title = {Optical clearing of archive-compatible paraffin embedded
             tissue for multiphoton microscopy.},
   Journal = {Biomedical Optics Express},
   Volume = {3},
   Number = {11},
   Pages = {2752-2760},
   Year = {2012},
   Month = {November},
   url = {http://www.ncbi.nlm.nih.gov/pubmed/23162713},
   Abstract = {Standard histopathology techniques (including paraffin
             embedding) are incompatible with thick tissue multiphoton
             imaging, and standard clearing techniques on those specimens
             destroy some molecular information. We demonstrate
             multiphoton imaging in specimens prepared according to
             standard histopathology techniques. This permits unlabeled
             3-dimensional histology on archival tissue banks, which is
             of great value in evaluating prognostic indicators.},
   Doi = {10.1364/BOE.3.002752},
   Key = {fds232523}
}

@article{fds232521,
   Author = {Li, B and Claytor, KE and Yuan, H and Vo-Dinh, T and Warren, WS and Fischer, MC},
   Title = {Multicontrast nonlinear optical microscopy with a compact
             and rapid pulse shaper.},
   Journal = {Optics Letters},
   Volume = {37},
   Number = {13},
   Pages = {2763-2765},
   Year = {2012},
   Month = {July},
   url = {http://www.ncbi.nlm.nih.gov/pubmed/22743521},
   Abstract = {Homodyne detection can dramatically enhance measurement
             sensitivity for weak signals. In nonlinear optical
             microscopy it can make accessible a range of novel,
             intrinsic, contrast like nonlinear absorption and nonlinear
             phase contrast. Here a compact and rapid pulse shaper is
             developed, implemented, and demonstrated for homodyne
             detection in nonlinear microscopy with high-repetition rate
             mode-locked femtosecond lasers. With this method we generate
             two-photon absorption (TPA) and self-phase modulation images
             of gold nanostars in biological samples. Simultaneous
             imaging of two-photon luminescence and TPA also enables us
             to produce two-photon quantum yield images.},
   Key = {fds232521}
}

@article{fds232519,
   Author = {Samineni, P and deCruz, A and Villafaña, TE and Warren, WS and Fischer,
             MC},
   Title = {Pump-probe imaging of historical pigments used in
             paintings.},
   Journal = {Optics Letters},
   Volume = {37},
   Number = {8},
   Pages = {1310-1312},
   Year = {2012},
   Month = {April},
   url = {http://www.ncbi.nlm.nih.gov/pubmed/22513669},
   Abstract = {A recently developed nonlinear optical pump-probe microscopy
             technique uses modulation transfer to sensitively extract
             excited-state dynamics of endogenous biological pigments,
             such as eumelanin and pheomelanin. In this work, we use this
             method to image and characterize several inorganic and
             organic pigments used in historical art. We show substantial
             differences in the near-IR pump-probe signatures from
             nominally similar pigments and suggest extensions to art
             restoration.},
   Key = {fds232519}
}

@article{fds232518,
   Author = {Samineni, P and Li, B and Wilson, JW and Warren, WS and Fischer,
             MC},
   Title = {Cross-phase modulation imaging.},
   Journal = {Optics Letters},
   Volume = {37},
   Number = {5},
   Pages = {800-802},
   Year = {2012},
   Month = {March},
   url = {http://www.ncbi.nlm.nih.gov/pubmed/22378398},
   Abstract = {We demonstrate a cross-phase modulation measurement
             technique based on the sensitive detection of modulation
             transfer in a pump-probe setup. By modulating the amplitude
             of the pump beam and spectrally analyzing the probe beam, we
             achieve a rapid, background-free measurement of nonlinear
             phase modulation using power levels acceptable in biological
             imaging. This measurement technique would allow the
             extension of widely employed phase microscopy methods to the
             nonlinear regime, providing intrinsic and universal
             nonlinear contrast for biological imaging.},
   Key = {fds232518}
}

@article{fds232516,
   Author = {Samineni, P and Cruz, AD and Villafana, T and Fischer, MC and Warren,
             WS},
   Title = {Pump-probe microscopy of pigments used in historical
             art},
   Journal = {2012 Conference on Lasers and Electro-Optics, CLEO
             2012},
   Year = {2012},
   Abstract = {We have developed a nonlinear microscopy technique that uses
             sensitive modulation transfer to extract excited state
             dynamics with high spatial resolution. Here, we use this
             technique to characterize several pigments used in
             historical artwork. © 2012 OSA.},
   Key = {fds232516}
}

@article{fds232517,
   Author = {Wilson, JW and Samineni, P and Fischer, MC and Warren,
             WS},
   Title = {Nonlinear cross-phase modulation microscopy using spectral
             shifting},
   Journal = {2012 Conference on Lasers and Electro-Optics, CLEO
             2012},
   Year = {2012},
   Abstract = {Nonlinear phase contrast may be acquired by measuring
             spectral shifting of an ultrafast pulse due to cross phase
             modulation. This technique is used to obtain structural
             details in a pigmented cell from a melanoma biopsy. © 2012
             OSA.},
   Key = {fds232517}
}

@article{fds232520,
   Author = {Wilson, JW and Samineni, P and Warren, WS and Fischer,
             MC},
   Title = {Cross-phase modulation spectral shifting: Nonlinear phase
             contrast in a pump-probe microscope},
   Journal = {Biomedical Optics Express},
   Volume = {3},
   Number = {5},
   Pages = {854-862},
   Year = {2012},
   ISSN = {2156-7085},
   url = {http://dx.doi.org/10.1364/BOE.3.000854},
   Abstract = {Microscopy with nonlinear phase contrast is achieved by a
             simple modification to a nonlinear pump-probe microscope.
             The technique measures cross-phase modulation by detecting a
             pump-induced spectral shift in the probe pulse. Images with
             nonlinear phase contrast are acquired both in transparent
             and absorptive media. In paraffin-embedded biopsy sections,
             cross-phase modulation complements the chemically-specific
             pump-probe images with structural context. © 2012 Optical
             Society of America.},
   Doi = {10.1364/BOE.3.000854},
   Key = {fds232520}
}

@article{fds232522,
   Author = {Robles, FE and Wilson, JW and Fischer, MC and Warren,
             WS},
   Title = {Phasor analysis for nonlinear pump-probe
             microscopy},
   Journal = {Optics express},
   Volume = {20},
   Number = {15},
   Pages = {17082-17092},
   Year = {2012},
   ISSN = {1094-4087},
   url = {http://dx.doi.org/10.1364/OE.20.017082},
   Abstract = {Pump-probe microscopy provides molecular information by
             probing transient, excited state dynamic properties of
             pigmented samples. Analysis of the transient response is
             typically conducted using principal component analysis or
             multi-exponential fitting, however these methods are not
             always practical or feasible. Here, we show an adaptation of
             phasor analysis to provide an intuitive, robust, and
             efficient method for analyzing and displaying pump-probe
             images, thereby alleviating some of the challenges
             associated with differentiating multiple pigments. A
             theoretical treatment is given to understand how the complex
             transient signals map onto the phasor plot. Analyses of
             cutaneous and ocular pigmented tissue samples, as well as
             historical pigments in art demonstrate the utility of this
             approach. ©2012 Optical Society of America.},
   Doi = {10.1364/OE.20.017082},
   Key = {fds232522}
}

@article{fds232525,
   Author = {Li, B and Yi, C and Brown, A and Fischer, MC and Warren,
             WS},
   Title = {Homodyne near-degenerate four-wave-mixing microscopy for
             graphene imaging and biomedical applications},
   Journal = {2012 Conference on Lasers and Electro-Optics, CLEO
             2012},
   Year = {2012},
   Abstract = {Homodyne detection of near-degenerate four-wave-mixing with
             a single laser pulse is used to imaging graphene in
             biological samples. © 2012 OSA.},
   Key = {fds232525}
}

@article{fds232486,
   Author = {Claytor, K and Li, B and Samineni, P and Warren, W and Fischer,
             M},
   Title = {Femtosecond pulse shaping enables nonlinear imaging in
             highly scattering materials},
   Journal = {Optics InfoBase Conference Papers},
   Year = {2011},
   Month = {December},
   Abstract = {Spectral re-shaping of pulses from a mode-locked femtosecond
             laser allows detection of two photon absorption and self
             phase modulation in highly scattering materials, which
             permits nonlinear tissue imaging with this intrinsic
             contrast. © 2011 OSA.},
   Key = {fds232486}
}

@article{fds232487,
   Author = {Samineni, P and Fischer, MC and Warren, WS},
   Title = {Cross-phase modulation microscopy},
   Journal = {Optics InfoBase Conference Papers},
   Year = {2011},
   Month = {December},
   Abstract = {We report our recently developed spectral re-shaping
             technique for cross-phase modulation imaging, which extends
             widely employed phase microscopy to the nonlinear regime. ©
             2011 OSA.},
   Key = {fds232487}
}

@article{fds232490,
   Author = {Li, B and Claytor, K and Warren, WS and Fischer, MC},
   Title = {Optimizing shape of femtosecond laser pulses for homodyne
             detection of nonlinear optical signals},
   Journal = {Optics InfoBase Conference Papers},
   Year = {2011},
   Month = {December},
   Abstract = {Based on homodyne detection of weak nonlinear signals with
             our spectral reshaping technique, pulse shapes are optimized
             for fast nonlinear imaging using femtosecond mode-locked
             lasers. © 2011 OSA.},
   Key = {fds232490}
}

@article{fds232485,
   Author = {Samineni, P and Fischer, MC and Liu, HC and Yasuda, R and Warren,
             WS},
   Title = {Nonlinear phase contrast imaging in neuronal
             tissue},
   Journal = {Optics InfoBase Conference Papers},
   Publisher = {Optical Society of America},
   Year = {2011},
   Abstract = {We demonstrate nonlinear phase contrast imaging in highly
             scattering media using rapid femtosecond pulse shaping of
             mode-locked laser pulses. We will also discuss potential
             applications of this technique for intrinsic functional
             neuronal imaging. © 2011 OSA: BODA/NTM/OMP/OTA.},
   Key = {fds232485}
}

@article{fds232488,
   Author = {Samineni, P and Fischer, MC and Liu, HC and Yasuda, R and Warren,
             WS},
   Title = {Nonlinear phase contrast imaging in neuronal
             tissue},
   Journal = {Optics InfoBase Conference Papers},
   Year = {2011},
   ISSN = {2162-2701},
   Key = {fds232488}
}

@article{fds232515,
   Author = {Li, B and Warren, WS and Fischer, MC},
   Title = {Phase-cycling coherent anti-Stokes Raman scattering using
             shaped femtosecond laser pulses.},
   Journal = {Optics express},
   Volume = {18},
   Number = {25},
   Pages = {25825-25832},
   Year = {2010},
   Month = {December},
   url = {http://www.ncbi.nlm.nih.gov/pubmed/21164927},
   Abstract = {We demonstrate a homodyne coherent anti-Stokes Raman
             scattering (CARS) technique based on femtosecond laser pulse
             shaping. This technique utilizes fast phase cycling to
             extract nonlinear Raman signatures with a self-generated
             reference signal acting as a local oscillator. The local
             oscillator is generated at the focus and is intrinsically
             stable relative to the Raman signal even in highly
             scattering samples. We can therefore retrieve phase
             information from the Raman signal and can suppress the
             ubiquitous non-resonant background.},
   Key = {fds232515}
}

@article{fds232483,
   Author = {Samineni, P and Perret, Z and Warren, WS and Fischer,
             MC},
   Title = {Femtosecond laser pulse shaping improves self-phase
             modulation measurements in scattering media},
   Journal = {Optics InfoBase Conference Papers},
   Year = {2010},
   Month = {December},
   Abstract = {We demonstrate that our recently developed spectral
             re-shaping technique improves the accuracy and precision of
             self-phase modulation measurements in scattering media over
             the conventional Z-scan method. © 2010 OSA/FiO/LS
             2010.},
   Key = {fds232483}
}

@article{fds232484,
   Author = {Li, B and Warren, WS and Fischer, MC},
   Title = {Enhancing coherent anti-stokes Raman scattering background
             suppression with phase cycled structured femtosecond laser
             pulses},
   Journal = {Optics InfoBase Conference Papers},
   Year = {2010},
   Month = {December},
   Abstract = {We demonstrate a homodyne coherent anti-Stokes Raman
             scattering technique based on femtosecond laser pulse
             shaping (phase-cycling). This technique utilizes a
             self-generated non-resonant background as a local oscillator
             to retrieve phase information of the Raman signal. © 2010
             OSA/FiO/LS 2010.},
   Key = {fds232484}
}

@article{fds232514,
   Author = {Samineni, P and Perret, Z and Warren, WS and Fischer,
             MC},
   Title = {Measurements of nonlinear refractive index in scattering
             media.},
   Journal = {Optics express},
   Volume = {18},
   Number = {12},
   Pages = {12727-12735},
   Year = {2010},
   Month = {June},
   url = {http://www.ncbi.nlm.nih.gov/pubmed/20588401},
   Abstract = {We have recently developed a spectral re-shaping technique
             to simultaneously measure nonlinear refractive index and
             nonlinear absorption. In this technique, the information
             about the nonlinearities is encoded in the frequency domain,
             rather than in the spatial domain as in the conventional
             Z-scan method. Here we show that frequency encoding is much
             more robust with respect to scattering. We compare spectral
             re-shaping and Z-scan measurements in a highly scattering
             environment and show that reliable spectral re-shaping
             measurements can be performed even in a regime that
             precludes standard Z-scans.},
   Key = {fds232514}
}

@article{fds232478,
   Author = {Warren, WS and Piletic, I and Fischer, M and Fu, D and Samenini, P and Matthews, T},
   Title = {Nonlinear microscopy without fluorescence: Seeing the needle
             in the Haystack with Femtosecond pulse shaping},
   Journal = {Optics InfoBase Conference Papers},
   Year = {2009},
   Month = {December},
   Key = {fds232478}
}

@article{fds232534,
   Author = {Piletic, IR and Fischer, MC and Samineni, P and Yurtsever, G and Warren,
             WS},
   Title = {Rapid pulse shaping with homodyne detection for measuring
             nonlinear optical signals.},
   Journal = {Optics Letters},
   Volume = {33},
   Number = {13},
   Pages = {1482-1484},
   Year = {2008},
   Month = {July},
   ISSN = {0146-9592},
   url = {http://www.ncbi.nlm.nih.gov/pubmed/18594672},
   Abstract = {We have designed a common-mode interferometric acousto-optic
             pulse shaper that is capable of shaping individual pulses
             differently from a mode-locked laser. The design enables the
             measurement of weak nonlinear optical signals such as
             two-photon absorption and self-phase modulation at megahertz
             rates. The experimental apparatus incorporates homodyne
             detection as a means of resolving the phase of the detected
             signals. The fast data acquisition rate and the ability to
             perform measurements in scattering media make this
             experimental apparatus amenable to imaging applications
             analogous to measurements of two-photon fluorescence using a
             mode-locked laser.},
   Key = {fds232534}
}

@article{fds232533,
   Author = {Fischer, MC and Liu, HC and Piletic, IR and Warren,
             WS},
   Title = {Simultaneous self-phase modulation and two-photon absorption
             measurement by a spectral homodyne Z-scan
             method.},
   Journal = {Optics express},
   Volume = {16},
   Number = {6},
   Pages = {4192-4205},
   Year = {2008},
   Month = {March},
   url = {http://www.ncbi.nlm.nih.gov/pubmed/18542515},
   Abstract = {We developed a technique to simultaneously measure
             self-phase modulation and two-photon absorption using shaped
             femtosecond laser pulses. In the conventional Z-scan
             measurement technique the amount of nonlinearity is
             determined by measuring the change in shape and intensity of
             a transmitted laser beam. In contrast, our method
             sensitively measures nonlinearity-induced changes in the
             pulse spectrum. In this work we demonstrate the technique in
             nonlinear absorptive and dispersive samples, quantify the
             obtained signal, and compare the measurements with
             traditional Z-scans. This technique is capable of measuring
             these nonlinearities in highly scattering
             samples.},
   Key = {fds232533}
}

@article{fds232535,
   Author = {Fischer, MC and Liu, HC and Piletic, IR and Escobedo-Lozoya, Y and Yasuda, R and Warren, WS},
   Title = {Self-phase modulation signatures of neuronal
             activity.},
   Journal = {Optics Letters},
   Volume = {33},
   Number = {3},
   Pages = {219-221},
   Year = {2008},
   Month = {February},
   ISSN = {0146-9592},
   url = {http://www.ncbi.nlm.nih.gov/pubmed/18246134},
   Abstract = {We use phase-sensitive detection of spectral hole refilling
             to demonstrate strong novel intrinsic nonlinear signatures
             of neuronal activation in hippocampal brain slices. The
             ability to gain access to this fundamentally new intrinsic
             contrast with modest power levels suggests a new approach to
             in vivo neural imaging. We expect that we can extrapolate
             our method to high spatial and temporal resolution in deep
             tissue while retaining the noninvasive character.},
   Key = {fds232535}
}

@article{fds232479,
   Author = {Liu, HC and Fischer, MC and Samineni, P and Escobedo-Lozoya, Y and Yasuda, R and Warren, WS},
   Title = {Intrinsic nonlinear optical signatures of neuronal
             activity},
   Journal = {Optics InfoBase Conference Papers},
   Year = {2008},
   Month = {January},
   Abstract = {Using novel femtosecond laser pulse shaping techniques and a
             virtually background-free detection strategy we demonstrate
             strong self-phase modulation signatures of neuronal activity
             in hippocampal brain slices without the use of exogenous
             contrast agents. © 2008 Optical Society of
             America.},
   Key = {fds232479}
}

@article{fds232480,
   Author = {Fischer, MC and Liu, HC and Fu, D and Semineni, P and Matthews, T and Piletic, I and Warren, WS},
   Title = {Femtosecond laser pulse shaping for molecular imaging in
             biological tissue},
   Journal = {Optics InfoBase Conference Papers},
   Year = {2008},
   Month = {January},
   Abstract = {Recently developed ultrafast laser pulse shaping technology
             allows highsensitivity measurements of nonlinear optical
             effects in highly scattering media. We present applications
             of these techniques to extract intrinsic structural,
             metabolic and functional contrast in biological tissue. ©
             2008 OSA.},
   Key = {fds232480}
}

@article{fds232481,
   Author = {Piletic, IR and Fischer, MC and Samineni, P and Warren,
             WS},
   Title = {Accessing nonlinear contrast in imaging using rapid pulse
             shaping techniques},
   Journal = {Optics InfoBase Conference Papers},
   Year = {2008},
   Month = {January},
   Abstract = {We have designed an interferometric acousto-optic pulse
             shaper capable of shaping individual pulses differently from
             a mode-locked laser. The design enables the measurement of
             weak nonlinear optical signals at megahertz (MHz) rates for
             imaging applications. © 2008 Optical Society of
             America.},
   Key = {fds232481}
}

@article{fds311243,
   Author = {Warren, WS and Fischer, M and Fu, D and Ye, T and Piletic, I and Matthews,
             T},
   Title = {New nonlinear signatures in spectroscopy and
             imaging},
   Journal = {Optics InfoBase Conference Papers},
   Year = {2008},
   Month = {January},
   Abstract = {Ultrafast laser pulse shaping makes it possible to observe
             nonlinear signatures, such as self phase modulation and sum
             frequency absorption, at safe laser powers for tissue.
             Neuronal activation and melanoma diagnosis are two early
             targets. ©2008 Optical Society of America.},
   Key = {fds311243}
}

@article{fds311313,
   Author = {Warren, WS and Fischer, M and Fu, D and Ye, T and Piletic, I and Matthews,
             T},
   Title = {New nonlinear signatures in spectroscopy and
             imaging},
   Journal = {Optics InfoBase Conference Papers},
   Year = {2008},
   Month = {January},
   Abstract = {Ultrafast laser pulse shaping makes it possible to observe
             nonlinear signatures, such as self phase modulation and sum
             frequency absorption, at safe laser powers for tissue.
             Neuronal activation and melanoma diagnosis are two early
             targets. © 2008 Optical Society of America.},
   Key = {fds311313}
}

@article{fds232532,
   Author = {Emami, K and Cadman, RV and Woodburn, JM and Fischer, MC and Kadlecek,
             SJ and Zhu, J and Pickup, S and Guyer, RA and Law, M and Vahdat, V and Friscia, ME and Ishii, M and Yu, J and Gefter, WB and Shrager, JB and Rizi,
             RR},
   Title = {Early changes of lung function and structure in an elastase
             model of emphysema - A hyperpolarized 3He MRI
             study},
   Journal = {Journal of applied physiology (Bethesda, Md. :
             1985)},
   Volume = {104},
   Number = {3},
   Pages = {773-786},
   Year = {2008},
   ISSN = {8750-7587},
   url = {http://dx.doi.org/10.1152/japplphysiol.00482.2007},
   Abstract = {Early changes of lung function and structure were studied in
             the presence of an elastase-induced model of emphysema in 35
             Sprague-Dawley rats at mild (5 U/100 g) and moderate (10
             U/100 g) severities. Lung ventilation was measured on a
             regional basis (at a planar resolution of 3.2 mm) by
             hyperpolarized 3He MRI at 5 and 10 wk after model induction.
             Subsequent to imaging, average alveolar diameter was
             measured from histological slices taken from the centers of
             each lobe. Changes of mean fractional ventilation, mean
             linear intercept, and intrasubject heterogeneity of
             ventilation were studied during disease progression. Mean
             fractional ventilation was significantly different between
             healthy controls (0.23 ± 0.04) and emphysematous animals at
             both time points in the 10-unit group (0.06 ± 0.02 and 0.12
             ± 0.05, respectively). Changes in average alveolar diameter
             were not statistically observable until the 10th wk between
             healthy (37 ± 10 μm) and emphysematous rats (73 ± 25 and
             95 ± 31 μm, for 5 and 10 units, respectively). Assessment
             of function-structure correlation suggested that the
             majority of the decline in fractional ventilation occurred
             in the first 5 wk, while enlargement of alveolar diameters
             appeared primarily between the 5th and 10th wk. A
             thresholding metric, based on the 20th percentile of
             fractional ventilation over the entire lung, was utilized to
             detect the onset of the disease with confidence, independent
             of whether the regional ventilation measurements were
             normalized with respect to the delivered tidal volume and
             estimated functional residual capacity of each individual
             rat.},
   Doi = {10.1152/japplphysiol.00482.2007},
   Key = {fds232532}
}

@article{fds311244,
   Author = {Warren, WS and Fischer, M and Fu, D and Ye, T and Piletic, I and Matthews,
             T},
   Title = {New nonlinear signatures in spectroscopy and
             imaging},
   Journal = {Conference on Quantum Electronics and Laser Science (QELS) -
             Technical Digest Series},
   Year = {2008},
   url = {http://dx.doi.org/10.1109/QELS.2008.4552901},
   Abstract = {Ultrafast laser pulse shaping makes it possible to observe
             nonlinear signatures, such as self phase modulation and sum
             frequency absorption, at safe laser powers for tissue.
             Neuronal activation and melanoma diagnosis are two early
             targets. © 2008 Optical Society of America.},
   Doi = {10.1109/QELS.2008.4552901},
   Key = {fds311244}
}

@article{fds232536,
   Author = {Warren, WS and Fischer, MC and Tong, Y},
   Title = {Novel nonlinear contrast improves deep-tissue
             microscopy},
   Journal = {Laser Focus World},
   Volume = {43},
   Number = {6},
   Pages = {99-103},
   Year = {2007},
   ISSN = {1043-8092},
   Abstract = {Femtosecond laser pulse and pulse-train shaping allow
             detection of new nonlinear effects, with modest powers,
             making new biomarkers accessible and permitting deeper
             tissue imaging than conventional microscopy. The most
             developed of these technique create light at a new
             wavelength, which can then be separated from the exciting
             laser. While the two photon fluorescence (TPF) can be
             induced by continuous wave lasers, the vast majority of
             studies use short laser pulses to achieve high peak power
             with relatively low tissue damage from average power
             dissipation. Two photon absorption (TPA) and self-phase
             modulation (SPM) are the two most important
             single-wavelength effect for the purpose of tissue
             engineering. TPA is more effective on the intense pulses
             than on the weak ones, and it thus distorts the amplitude
             modulation, creating extra sidebands. Microscopic resolution
             to depths of about 1mm should be achievable in most tissues
             with far more physiological contrast than conventional
             microscopy.},
   Key = {fds232536}
}

@article{fds232476,
   Author = {Warren, WS and Ye, T and Fischer, M and Yurtsever, G and Li, C and Liu, H and Fu, D},
   Title = {Deep tissue imaging with shaped femtosecond laser
             pulses},
   Journal = {Optics InfoBase Conference Papers},
   Year = {2006},
   Month = {January},
   Abstract = {Two-photon absorption and self phase modulation can be
             detected deep in tissue with modest laser powers, using
             shaped femtosecond pulses. This permit microscopic-resolution
             images of biologically important targets. © 2006 Optical
             Society of America.},
   Key = {fds232476}
}

@article{fds311242,
   Author = {Ye, T and Fischer, M and Yurtsever, G and Warren,
             WS},
   Title = {Two-photon absorption microscopy of tissue},
   Journal = {Optics InfoBase Conference Papers},
   Year = {2006},
   Month = {January},
   ISSN = {2162-2701},
   Abstract = {Two-photon absorption microscopy (TPAM) has been
             demonstrated to be able to image melanin with high
             sensitivity. TPAM opens up a wide range of nonfluorescent
             molecular targets. © 2005 Optical Society of
             America.},
   Key = {fds311242}
}

@article{fds232509,
   Author = {Kadlecek, SJ and Emami, K and Fischer, MC and Ishii, M and Yu, J and Woodburn, JM and NikKhah, M and Vahdat, V and Lipson, DA and Baumgardner, JE and Rizi, RR},
   Title = {Corrigendum to "Imaging physiological parameters with
             hyperpolarized gas MRI" Progress in NMR Spectrosc. 47 (2005)
             187 (DOI:10.1016/j.pnmrs.2005.08.006)},
   Journal = {Progress in Nuclear Magnetic Resonance Spectroscopy},
   Volume = {48},
   Number = {4},
   Pages = {233-235},
   Year = {2006},
   ISSN = {0079-6565},
   url = {http://dx.doi.org/10.1016/j.pnmrs.2006.05.001},
   Doi = {10.1016/j.pnmrs.2006.05.001},
   Key = {fds232509}
}

@article{fds232475,
   Author = {Fischer, MC and Ye, T and Yurtsever, G and Miller, A and Ciocca, M and Wagner, W and Warren, WS},
   Title = {Two-photon absorption and self-phase modulation measurements
             with shaped femtosecond laser pulses},
   Journal = {2005 Conference on Lasers and Electro-Optics,
             CLEO},
   Volume = {2},
   Pages = {968-970},
   Year = {2005},
   Month = {December},
   ISSN = {2162-2701},
   Abstract = {We demonstrate experimentally that phase sensitive detection
             of spectral hole refilling can yield information about
             self-phase modulation and two-photon absorption
             coefficients. © 2005 Optical Society of
             America.},
   Key = {fds232475}
}

@article{fds304370,
   Author = {Spector, ZZ and Emami, K and Fischer, MC and Zhu, J and Ishii, M and Vahdat, V and Yu, J and Kadlecek, S and Driehuys, B and Lipson, DA and Gefter, W and Shrager, J and Rizi, RR},
   Title = {Quantitative assessment of emphysema using hyperpolarized
             3He magnetic resonance imaging.},
   Journal = {Magnetic Resonance in Medicine},
   Volume = {53},
   Number = {6},
   Pages = {1341-1346},
   Year = {2005},
   Month = {June},
   ISSN = {0740-3194},
   url = {http://www.ncbi.nlm.nih.gov/pubmed/15906306},
   Abstract = {In this experiment, Sprague-Dawley rats with
             elastase-induced emphysema were imaged using hyperpolarized
             (3)He MRI. Regional fractional ventilation r, the fraction
             of gas replaced with a single tidal breath, was calculated
             from a series of images in a wash-in study of hyperpolarized
             gas. We compared the regional fractional ventilation in
             these emphysematous rats to the regional fractional
             ventilations we calculated from a previous baseline study in
             healthy Sprague-Dawley rats. We found that there were
             differences in the maps of fractional ventilation and its
             associated frequency distribution between the healthy and
             emphysematous rat lungs. Fractional ventilation tended to be
             much lower in emphysematous rats than in normal rats. With
             this information, we can use data on fractional ventilation
             to regionally distinguish between healthy and emphysematous
             portions of the lung. The successful implementation of such
             a technique on a rat model could lead to work toward the
             future implementation of this technique in human
             patients.},
   Doi = {10.1002/mrm.20514},
   Key = {fds304370}
}

@article{fds232473,
   Author = {Fischer, MC and Ye, T and Yurtsever, G and Miller, A and Ciocca, M and Wagner, W and Warren, WS},
   Title = {Two-photon absorption and self-phase modulation measurements
             with shaped femtosecond laser pulses},
   Journal = {Optics InfoBase Conference Papers},
   Year = {2005},
   ISSN = {2162-2701},
   Abstract = {We demonstrate experimentally that phase sensitive detection
             of spectral hole refilling can yield information about
             self-phase modulation and two-photon absorption
             coefficients. © 2005 Optical Society of
             America.},
   Key = {fds232473}
}

@article{fds232541,
   Author = {Kadlecek, SJ and Emami, K and Fischer, MC and Ishii, M and Yu, J and Woodburn, JM and NikKhah, M and Vahdat, V and Lipson, DA and Baumgardner, JE and Rizi, RR},
   Title = {Imaging physiological parameters with hyperpolarized gas
             MRI},
   Journal = {Progress in Nuclear Magnetic Resonance Spectroscopy},
   Volume = {47},
   Number = {3-4},
   Pages = {187-212},
   Year = {2005},
   ISSN = {0079-6565},
   url = {http://dx.doi.org/10.1016/j.pnmrs.2005.08.006},
   Abstract = {A survey capable of producing the desired physiological
             information from a series of polarized gas MR images is
             discussed. Salient requirements of an ideal radiological
             method for quantitative assessment of lung function are also
             discussed. The benefits of polarized gas MRI are clarified
             through a comparison with other existing modalities. The
             optical pumping methods for the generation of
             hyperpolarization and the technical aspects of gas delivery
             and storage are presented. Imaging techniques such as
             MR-based coronary angiography, and PET/SPECT tests have
             advanced together with extremely effective therapies and
             surgical procedures.},
   Doi = {10.1016/j.pnmrs.2005.08.006},
   Key = {fds232541}
}

@article{fds232542,
   Author = {Ishii, M and Fischer, MC and Emami, K and Alavi, A and Spector, ZZ and Yu,
             J and Baumgardner, JE and Itkin, M and Kadlecek, SJ and Zhu, J and Bono, M and Gefter, WB and Lipson, DA and Shrager, JB and Rizi,
             RR},
   Title = {Hyperpolarized helium-3 MR imaging of pulmonary
             function},
   Journal = {Radiologic Clinics of North America},
   Volume = {43},
   Number = {1},
   Pages = {235-246},
   Year = {2005},
   url = {http://dx.doi.org/10.1016/j.rcl.2004.09.010},
   Abstract = {Recent advances in HP MR imaging contrast agents have led to
             novel tests of pulmonary function. Many of these tests show
             promise in the clinical arena.},
   Doi = {10.1016/j.rcl.2004.09.010},
   Key = {fds232542}
}

@article{fds232544,
   Author = {Spector, ZZ and Emami, K and Fischer, MC and Zhu, J and Ishii, M and Vahdat, V and Yu, J and Kadlecek, S and Driehuys, B and Lipson, DA and Gefter, W and Shrager, J and Rizi, RR},
   Title = {Quantitative assessment of emphysema using hyperpolarized
             3He MRI},
   Journal = {Mag. Res. Med.},
   Volume = {53},
   Number = {6},
   Pages = {1341},
   Year = {2005},
   ISSN = {0740-3194},
   url = {http://www.ncbi.nlm.nih.gov/pubmed/15906306},
   Abstract = {In this experiment, Sprague-Dawley rats with
             elastase-induced emphysema were imaged using hyperpolarized
             (3)He MRI. Regional fractional ventilation r, the fraction
             of gas replaced with a single tidal breath, was calculated
             from a series of images in a wash-in study of hyperpolarized
             gas. We compared the regional fractional ventilation in
             these emphysematous rats to the regional fractional
             ventilations we calculated from a previous baseline study in
             healthy Sprague-Dawley rats. We found that there were
             differences in the maps of fractional ventilation and its
             associated frequency distribution between the healthy and
             emphysematous rat lungs. Fractional ventilation tended to be
             much lower in emphysematous rats than in normal rats. With
             this information, we can use data on fractional ventilation
             to regionally distinguish between healthy and emphysematous
             portions of the lung. The successful implementation of such
             a technique on a rat model could lead to work toward the
             future implementation of this technique in human
             patients.},
   Doi = {10.1002/mrm.20514},
   Key = {fds232544}
}

@article{fds232545,
   Author = {Fischer, MC and Ye, T and Yurtsever, G and Miller, A and Ciocca, M and Wagner, W and Warren, WS},
   Title = {Two-photon absorption and self-phase modulation measurements
             with shaped femtosecond laser pulses},
   Journal = {Optics Letters},
   Volume = {30},
   Number = {12},
   Pages = {1551-1553},
   Year = {2005},
   ISSN = {0146-9592},
   url = {http://dx.doi.org/10.1364/OL.30.001551},
   Abstract = {We show that phase-sensitive detection of spectral hole
             refilling can yield information about self-phase modulation
             and two-photon absorption coefficients. We expect that, when
             applied to tissue microscopy, this technique will allow the
             study of endogenous molecular markers beneath the surface,
             even if those markers are nonfluorescent. © 2005 Optical
             Society of America.},
   Doi = {10.1364/OL.30.001551},
   Key = {fds232545}
}

@article{fds232552,
   Author = {Fischer, MC and Kadlecek, S and Yu, J and Ishii, M and Emami, K and Vahdat,
             V and Lipson, DA and Rizi, RR},
   Title = {Measurements of regional alveolar oxygen pressure using
             hyperpolarized 3He MRI},
   Journal = {Academic Radiology},
   Volume = {12},
   Number = {11},
   Pages = {1430-1439},
   Year = {2005},
   ISSN = {1076-6332},
   url = {http://dx.doi.org/10.1016/j.acra.2005.07.007},
   Abstract = {Rationale and Objectives. The aim of this work is to review
             hyperpolarized (HP) helium-3 (3He) magnetic resonance
             imaging (MRI) methods to measure regional alveolar oxygen
             partial pressure (PAo2) and oxygen depletion rate (R) in the
             lung. We point out limitations of the methods and suggest
             improvements to increase their accuracy. Materials and
             Methods. PAO2 and R can be extracted from series of HP gas
             images acquired during breath hold by making use of the
             depolarizing effect of oxygen on HP gas. To separate
             oxygen-induced depolarization from other depolarizing
             effects, several techniques can be used. We review currently
             used techniques and point out their advantages and
             limitations. Results. We show that the precision of oxygen
             measurements depends on a variety of parameters and can vary
             within the measurement volume. Accuracy of the measurement
             also can be influenced by diffusion of oxygen and polarized
             3He and generally is different for single-slice and
             multislice measurements. We present numerical simulations,
             phantom data, and in vivo data for illustration. Conclusion.
             HP 3He MRI is a noninvasive, nonionizing, and repeatable
             imaging method that allows for quantitative analysis of lung
             function. The current techniques for measuring PAO2 have the
             potential to deliver clinically relevant functional images.
             © AUR, 2005.},
   Doi = {10.1016/j.acra.2005.07.007},
   Key = {fds232552}
}

@article{fds232553,
   Author = {Haczku, A and Emami, K and Fischer, MC and Kadlecek, S and Ishii, M and Panettieri, RA and Rizi, RR},
   Title = {Hyperpolarized 3He MRI in asthma: Measurements of
             regional ventilation following allergic sensitization and
             challenge in mice - Preliminary results},
   Journal = {Academic Radiology},
   Volume = {12},
   Number = {11},
   Pages = {1362-1370},
   Year = {2005},
   ISSN = {1076-6332},
   url = {http://dx.doi.org/10.1016/j.acra.2005.08.027},
   Abstract = {Rationale and Objectives. Quantitative regional measurement
             of physiological parameters of lung may improve both early
             detection of asthma and its response to treatment by
             elucidating the characteristics of airway obstruction.
             Recent emergence of hyperpolarized helium-3 magnetic
             resonance imaging as a sensitive pulmonary imaging tool has
             shown great potential in capturing important structural and
             functional aspects of normal and diseased lungs. The
             objective of this study was to investigate regional
             ventilation changes in the mouse lung following allergen
             sensitization and challenge. Materials and Methods. A murine
             model of allergic airway inflammation was created in mice
             following allergen challenge using Af and IgE-mediated
             asthma. The creation of model was verified using pulmonary
             function test and histology. Regional fractional ventilation
             was then measured in the animals using hyperpolarized 3He
             MRI on a pixel-by-pixel basis with a planar resolution of
             0.24 mm. The sensitized and healthy animals were then
             compared statisticall to assess the potential sensitivity of
             this technique in detection of such pulmonary abnormalities.
             Results. In this work, we have demonstrated for the first
             time the quantitative measurement of regional ventilation in
             normal and asthmatic mice. Results of this study show
             significant changes in regional ventilation in murine model
             of allergic airway sensitization compared with that in
             normal control animals. Conclusion. Further development of
             this technique can potentially serve as a quantitative
             marker to investigate the physiology of allergen-induced
             airway hyperresponsiveness and to assist in disease
             treatment and prevention. © AUR, 2005.},
   Doi = {10.1016/j.acra.2005.08.027},
   Key = {fds232553}
}

@article{fds232543,
   Author = {Spector, ZZ and Emami, K and Fischer, MC and Zhu, J and Ishii, M and Yu, J and Kadlecek, S and Driehuys, B and Panettieri, RA and Lipson, DA and Gefter, W and Shrager, J and Rizi, RR},
   Title = {A small animal model of regional alveolar ventilation using
             HP 3He MRI1.},
   Journal = {Academic Radiology},
   Volume = {11},
   Number = {10},
   Pages = {1171-1179},
   Year = {2004},
   Month = {October},
   ISSN = {1076-6332},
   url = {http://www.ncbi.nlm.nih.gov/pubmed/15530811},
   Abstract = {RATIONALE AND OBJECTIVES: The aim of this study was to
             establish a standardized procedure for the measurement of
             regional fractional ventilation in a healthy rat model as a
             baseline for further studies of pulmonary disorder models.
             MATERIALS AND METHODS: The lungs of five healthy male
             Sprague-Dawley rats were imaged using hyperpolarized
             helium-3 magnetic resonance imaging. From these images,
             regional fractional ventilation was calculated and maps
             generated detailing the distribution of fractional
             ventilation in the lung. The 1.56 mm x 1.56 mm x 4 mm
             regions of interest were assigned on 5 cm x 5 cm field of
             view lung maps. Histograms were also generated showing the
             frequency distribution of fractional ventilation values. To
             compare fractional ventilation values between animals, the
             ventilation procedure was standardized to results from
             individual pulmonary function tests. Each animal's
             spontaneous tidal volume, respiratory rate, and inspiration
             percentage (percent of total respiratory cycle in
             inspiration) were used in their mechanical ventilation
             settings. RESULTS: Results were similar among all five
             healthy rats based on examination of ventilation
             distribution maps and frequency distribution histograms.
             Mean (0.13) and standard deviation (0.07) were calculated
             for fractional ventilation in each animal. However, these
             values were determined to be influenced by slice selection,
             and therefore the maps and histograms were favored in
             analysis of results. CONCLUSION: This study shows consistent
             results in healthy rat lungs and will serve as a baseline
             study for future measurements in emphysematous rat
             lungs.},
   Doi = {10.1016/j.acra.2004.08.001},
   Key = {fds232543}
}

@article{fds232540,
   Author = {Fischer, MC and Spector, ZZ and Ishii, M and Yu, J and Emami, K and Itkin,
             M and Rizi, R},
   Title = {Single-acquisition sequence for the measurement of oxygen
             partial pressure by hyperpolarized gas MRI},
   Journal = {Magnetic Resonance in Medicine},
   Volume = {52},
   Number = {4},
   Pages = {766-773},
   Year = {2004},
   url = {http://dx.doi.org/10.1002/mrm.20239},
   Abstract = {Magnetic resonance imaging (MRI) with hyperpolarized
             3-helium gas (HP 3He) offers the possibility of studying
             functional lung parameters such as the alveolar oxygen
             concentration and oxygen depletion rate. Until now, a
             double-acquisition technique has been utilized to extract
             these parameters. A complicated single-acquisition technique
             was previously developed to avoid the necessity of
             performing two identical breathing maneuvers. The results
             obtained with this technique were significantly less
             accurate than the results obtained with the
             double-acquisition method. In this work, a novel, easily
             implemented single-acquisition sequence is presented that
             provides results comparable to those obtained with the
             established double-acquisition method. This method is
             demonstrated in a phantom and a pig model on a 1.5 T scanner
             using a 2D fast low-angle shot (FLASH) gradient-echo
             sequence. Numerical simulations of the time evolution of the
             oxygen concentration were performed. Simulation results are
             presented to support the experimental data. Various
             parameter regimes were experimentally and numerically
             investigated. © 2004 Wiley-Liss, Inc.},
   Doi = {10.1002/mrm.20239},
   Key = {fds232540}
}

@article{fds232539,
   Author = {Fischer, MC and Gupta, GC and Wang, LL and Kojima, K and Mizuhara, O and Swaminathan, V},
   Title = {FEC performance under optical power transient
             conditions},
   Journal = {IEEE Photonics Technology Letters},
   Volume = {15},
   Number = {11},
   Pages = {1654-1656},
   Year = {2003},
   url = {http://dx.doi.org/10.1109/LPT.2003.818665},
   Abstract = {We report the investigation of the performance of an
             interleaved Reed-Solomon forward error correction code in
             the presence of optical power transients for the first time.
             These transients were generated by adding-dropping channels
             in an erbium-doped fiber amplifier or Raman amplified
             systems.},
   Doi = {10.1109/LPT.2003.818665},
   Key = {fds232539}
}

@article{fds232551,
   Author = {Soole, JBD and Pafchek, R and Narayanan, C and Bogert, G and Jampanaboyana, L and Chand, N and Yu, J and Fischer, M and Ling, M and Earnshaw, MP and Kojima, K and Swaminathan, V},
   Title = {DWDM performance of a packaged reconfigurable optical
             add-drop multiplexer subsystem supporting modular systems
             growth},
   Journal = {IEEE Photonics Technology Letters},
   Volume = {15},
   Number = {11},
   Pages = {1600-1602},
   Year = {2003},
   url = {http://dx.doi.org/10.1109/LPT.2003.818673},
   Abstract = {We describe dense wavelength-division-multiplexing (DWDM)
             operation of a reconfigurable optical add-drop multiplexer
             subsystem module employing silica waveguide technology that
             is suitable for use with both fixed-wavelength and
             wavelength-selectable add-drop transceivers. We illustrate
             its use in providing modular growth in high channel-count
             DWDM systems.},
   Doi = {10.1109/LPT.2003.818673},
   Key = {fds232551}
}

@article{fds232503,
   Author = {Kojima, K and Fischer, MC and Chand, N and Klotzkin, D and Kiely, PA and Sheridan-Eng, J and Xu, Y and Tohmon, G},
   Title = {Effect of reflection on un-isolated spot-size-converted 1.3
             μm DFB lasers for 2.5 Gbit/s transmission},
   Journal = {Conference on Optical Fiber Communication, Technical Digest
             Series},
   Volume = {70},
   Pages = {473-475},
   Year = {2002},
   Abstract = {Spot-size-converted 1.3 μm distributed feedback laser
             transmitter modules for 2.5 Gbit/s transmission, were
             fabricated. The laser was mounted on a submount, and fiber
             coupling was done passively. Reflection was defined as the
             ratio of optical power coming back into the transmitter. The
             lasers satisfied the SDH/SONET requirements for 15 km
             transmission with strong reflection up to -16.5 dB at
             various locations.},
   Key = {fds232503}
}

@article{fds232549,
   Author = {Shin, DS and Wang, J and Bosch, F and Kiely, PA and Chand, N and Fischer,
             M and Kojima, K and Kasper, BL and Peral, EM and Ransijn,
             H},
   Title = {10 gbit/s transmission over 50 km nonzero dispersion-shifted
             fibre using 1.3 μm directly modulated uncooled
             transmitters},
   Journal = {Electronics Letters},
   Volume = {38},
   Number = {16},
   Pages = {864-865},
   Year = {2002},
   ISSN = {0013-5194},
   url = {http://dx.doi.org/10.1049/el:20020606},
   Abstract = {A 1.3 μm uncooled transmitter with wide-open eye diagrams
             at laser temperatures of 20, 50, and 85°C is presented.
             Using this transmitter, it is demonstrated that 10 Gbit/s
             transmission is possible over a 50 km nonzero
             dispersion-shifted Lucent TrueWave-RS fibre. This result is
             compared with transmission over a 55 km standard singlemode
             fibre.},
   Doi = {10.1049/el:20020606},
   Key = {fds232549}
}

@article{fds232550,
   Author = {Yu, J and Fischer, M and Chand, N and Kojima, K and Swaminathan,
             V},
   Title = {10-Gb/s transmission over 200-km conventional fiber without
             dispersion compensation using the bias control
             technique},
   Journal = {IEEE Photonics Technology Letters},
   Volume = {14},
   Number = {12},
   Pages = {1746-1748},
   Year = {2002},
   url = {http://dx.doi.org/10.1109/LPT.2002.804668},
   Abstract = {Transmission of 10-Gb/s nonreturn-to-zero (NRZ) signal over
             200 km conventional single-mode fiber without any dispersion
             compensation was discussed. A bias control technique
             involving simultaneous charge of α parameter of an LiNbO3
             modulator (LN-MOD) and the extinction ratio was used. It was
             found that when the bias is shifted and the modulated
             voltage on the LN-MOD is fixed the chirp and the ER are
             changed simultaneously.},
   Doi = {10.1109/LPT.2002.804668},
   Key = {fds232550}
}

@article{fds232501,
   Author = {Yu, J and Kojima, K and Chand, N and Fischer, MC and Espindola, R and Mason, TGB},
   Title = {160GB/s single-channel unrepeatered transmission over 200km
             of non-zero dispersion shifted fiber},
   Journal = {European Conference on Optical Communication,
             ECOC},
   Volume = {6},
   Pages = {20-21},
   Year = {2001},
   Abstract = {Single-channel 160Gb/s unrepeated transmission over 200km of
             non-zero dispersion shifted fiber (NZDSF) was reported using
             distributed Raman amplification. Clock recovery and
             demultiplexing were realized simultaneously by cascading a
             tandem electro-absorption modulator (TEAM and another EAM.
             When 160Gbit/s signal was transmitted over 175km fiber span,
             the power penalty was found to be 1.8dB.},
   Key = {fds232501}
}

@article{fds232504,
   Author = {Fischer, MC and Dudarev, AM and Gutiérrez-Medina, B and Raizen,
             MG},
   Title = {FM spectroscopy in recoil-induced resonances},
   Journal = {Journal of Optics B: Quantum and Semiclassical
             Optics},
   Volume = {3},
   Number = {4},
   Pages = {279-287},
   Year = {2001},
   url = {http://dx.doi.org/10.1088/1464-4266/3/4/313},
   Abstract = {We report on an experimental study of recoil-induced
             resonances as a method of velocimetry for cold atomic
             samples. We present a refined experimental method that
             greatly improves the sensitivity of the measurement over
             previous experiments. Using frequency-modulation (FM)
             spectroscopy techniques we achieve a sensitivity that
             approaches the shot noise limit. In addition, we present a
             novel approach to deriving the line shape of the observed
             signal, based on the concept of quantum transport and
             tunnelling in motional Bloch bands.},
   Doi = {10.1088/1464-4266/3/4/313},
   Key = {fds232504}
}

@article{fds232538,
   Author = {Fischer, MC and Gutiérrez Medina and B and Raizen,
             MG},
   Title = {Observation of the quantum Zeno and anti-Zeno effects in an
             unstable system},
   Journal = {Phys. Rev. Lett.},
   Volume = {87},
   Number = {4},
   Pages = {040402},
   Year = {2001},
   ISSN = {0031-9007},
   Abstract = {The first observation of the quantum Zeno and anti-Zeno
             effects in an unstable system was experimentally studied.
             The number of atoms remaining trapped during the initial
             period of nonexponential decay also measured. The results
             reveal that number of trapped atoms show strong
             nonexponential decay features, evolving into the
             characteristic exponential decay behavior.},
   Key = {fds232538}
}

@article{fds304369,
   Author = {Fischer, MC and Gutiérrez-Medina, B and Raizen,
             MG},
   Title = {Observation of the quantum Zeno and anti-Zeno effects in an
             unstable system},
   Journal = {Physical Review Letters},
   Volume = {87},
   Number = {4},
   Pages = {404021-404024},
   Year = {2001},
   ISSN = {0031-9007},
   Abstract = {The first observation of the quantum Zeno and anti-Zeno
             effects in an unstable system was experimentally studied.
             The number of atoms remaining trapped during the initial
             period of nonexponential decay also measured. The results
             reveal that number of trapped atoms show strong
             nonexponential decay features, evolving into the
             characteristic exponential decay behavior.},
   Key = {fds304369}
}

@article{fds232548,
   Author = {Madison, KW and Fischer, MC and Raizen, MG},
   Title = {Observation of the Wannier-Stark fan and the fractional
             ladder in an accelerating optical lattice},
   Journal = {Physical Review A - Atomic, Molecular, and Optical
             Physics},
   Volume = {60},
   Number = {3},
   Pages = {R1767-R1770},
   Year = {1999},
   Abstract = {We report an experimental study of the Wannier-Stark fan and
             the fractional Wannier-Stark ladder using laser-cooled
             sodium atoms in an accelerating one-dimensional standing
             wave of light. We prepare the atoms in the lowest motional
             band of the optical lattice and then impose a constant
             acceleration. A weak oscillatory component is added to the
             acceleration in order to resonantly drive interband
             transitions, and the number of atoms that remain in the
             lowest band is measured as a function of the probe
             frequency. The spectrum is characterized by a ladder of
             resonances spaced by the atomic Bloch oscillation frequency
             ωB. When an additional, strong ac component at frequency
             Ωis added, a fractional ladder is observed with a spacing
             related to the electric matching ratio Ω/ωB. ©1999 The
             American Physical Society.},
   Key = {fds232548}
}

@article{fds232527,
   Author = {Madison, KW and Fischer, MC and Niu, Q and Raizen,
             MG},
   Title = {Nonexponential decay in atomic tunneling},
   Journal = {Technical Digest - European Quantum Electronics
             Conference},
   Pages = {24-},
   Year = {1998},
   Abstract = {A simple model of the band structure with a single (trapped)
             band separated by a bandgap from a free particle state is
             used to study short-time deviation from exponential decay in
             a quantum tunneling experiment. The system consists of
             ultracold sodium atoms that are trapped in an accelerating
             periodic optical potential created by a standing wave of
             light. Atoms can escape the wells via a quantum tunneling,
             and the number that remain is measured as a function of
             interaction time for a fixed value of the well depth and
             acceleration.},
   Key = {fds232527}
}

@article{fds232537,
   Author = {Fischer, MC and Madison, KW and Niu, Q and Raizen,
             MG},
   Title = {Observation of Rabi oscillations between Bloch bands in an
             optical potential},
   Journal = {Phys. Rev. A},
   Volume = {58},
   Pages = {R2648},
   Year = {1998},
   Key = {fds232537}
}

@article{fds232547,
   Author = {Madison, KW and Fischer, MC and Diener, RB and Niu, Q and Raizen,
             MG},
   Title = {Dynamical bloch band suppression in an optical
             lattice},
   Journal = {Physical Review Letters},
   Volume = {81},
   Number = {23},
   Pages = {5093-5096},
   Year = {1998},
   Abstract = {Dynamical Bloch hand suppression is observed for the first
             time, using cold sodium atoms in a far detuned standing wave
             of light. This system has well-defined Bloch hands as its
             energy spectrum, which are modified dynamically by imposing
             a strong phase modulation of the standing wave. The atoms
             are prepared in the lowest band, and the spectrum is mapped
             out by introducing a weak spectroscopic probe that drives
             transitions between the modified bands. Dynamical
             suppression of the bands is observed at a critical value of
             the modulation strength, and is well supported by a full
             quantum mechanical analysis that goes beyond the single-band
             and light-binding approximations.},
   Key = {fds232547}
}

@article{fds232546,
   Author = {Wilkinson, SR and Bharucha, CF and Fischer, MC and Madison, KW and Morrow, PR and Niu, Q and Sundaram, B and Raizen,
             MG},
   Title = {Experimental evidence for non-exponential decay in quantum
             tunnelling},
   Journal = {Nature},
   Volume = {387},
   Number = {6633},
   Pages = {575-577},
   Year = {1997},
   url = {http://dx.doi.org/10.1038/42418},
   Abstract = {An exponential decay law is the universal hallmark of
             unstable systems and is observed in all fields of science.
             This law is not, however, fully consistent with quantum
             mechanics and deviations from exponential decay have been
             predicted for short as well as long times. Such deviations
             have not hitherto been observed experimentally. Here we
             present experimental evidence for short-time deviation from
             exponential decay in a quantum tunnelling experiment. Our
             system consists of ultra-cold sodium atoms that are trapped
             in an accelerating periodic optical potential created by a
             standing wave of light. Atoms can escape the wells by
             quantum tunnelling, and the number that remain can be
             measured as a function of interaction time for a fixed value
             of the well depth and acceleration. We observe that for
             short times the survival probability is initially constant
             before developing the characteristics of exponential decay.
             The conceptual simplicity of the experiment enables a
             detailed comparison with theoretical predictions.},
   Doi = {10.1038/42418},
   Key = {fds232546}
}


%% Chapter in Book   
@misc{fds232513,
   Author = {Fischer, MC and Raizen, MG},
   Title = {Experiments on quantum transport of ultra-cold atoms in
             optical potentials},
   Journal = {Lecture Notes in Physics},
   Volume = {789},
   Pages = {205-237},
   Booktitle = {Time in Quantum Mechanics},
   Publisher = {Springer},
   Year = {2009},
   ISSN = {0075-8450},
   url = {http://dx.doi.org/10.1007/978-3-642-03174-8_8},
   Abstract = {In this chapter, we describe our experiments with ultra cold
             atoms in optical potentials and show how we can address
             fundamental issues of time in quantum mechanics. The high
             degree of experimental control and the conceptual simplicity
             are the main advantages of our system. We start with an
             overview of the basic interaction of atoms and light and
             make the connection between atoms in optical lattices and
             solid state physics. While this latter connection has
             evolved into a major theme in physics over the past decade,
             at the time of this work it was still new and unexplored.
             After introduction of the theoretical model and the basic
             equations, we introduce the experimental apparatus. We then
             review our experiments to observe the Wannier-Stark ladder
             in an accelerating lattice. This system was used to study
             quantum tunneling where short-time non-exponential decay was
             first observed for an unstable quantum system. We then
             describe our experiments to observe the quantum Zeno and
             anti-Zeno effects for an unstable system that is repeatedly
             interrogated. We conclude this chapter with a brief outlook
             into the future. © 2010 Springer-Verlag Berlin
             Heidelberg.},
   Doi = {10.1007/978-3-642-03174-8_8},
   Key = {fds232513}
}