%% Books @book{fds326197, Author = {Guenther, BD}, Title = {Modern Optics Second Edition 978-0198738770}, Pages = {752 pages}, Publisher = {Oxford University Press}, Year = {2015}, Month = {December}, ISBN = {0198738773}, url = {http://dx.doi.org/10.1093/acprof:oso/9780198738770.001.0001}, Abstract = {Modern Optics is a fundamental study of the principles of optics using a rigorous physical approach based on Maxwell's Equations. The treatment provides the mathematical foundations needed to understand a number of applications such as laser optics, fiber optics and medical imaging covered in an engineering curriculum as well as the traditional topics covered in a physics based course in optics. In addition to treating the fundamentals in optical science, the student is given an exposure to actual optics engineering problems such as paraxial matrix optics, aberrations with experimental examples, Fourier transform optics (Fresnel-Kirchhoff formulation), Gaussian waves, thin films, photonic crystals, surface plasmons, and fiber optics. Through its many pictures, figures, and diagrams, the text provides a good physical insight into the topics covered. The course content can be modified to reflect the interests of the instructor as well as the student, through the selection of optional material provided in appendixes.}, Doi = {10.1093/acprof:oso/9780198738770.001.0001}, Key = {fds326197} } %% Papers Published @article{fds327562, Author = {Knobel-Dail, RB and Holditch-Davis, D and Sloane, R and Guenther, BD and Katz, LM}, Title = {Body temperature in premature infants during the first week of life: Exploration using infrared thermal imaging}, Journal = {Journal of Thermal Biology}, Volume = {69}, Pages = {118-123}, Year = {2017}, Month = {October}, url = {http://dx.doi.org/10.1016/j.jtherbio.2017.06.005}, Doi = {10.1016/j.jtherbio.2017.06.005}, Key = {fds327562} } @article{fds326018, Author = {McCain, ST and Guenther, BD and Brady, DJ and Krishnamurthy, K and Willett, R}, Title = {Coded-aperture Raman imaging for standoff explosive detection}, Journal = {Proceedings of SPIE - The International Society for Optical Engineering}, Volume = {8358}, Year = {2012}, url = {http://dx.doi.org/10.1117/12.919292}, Abstract = {This paper describes the design of a deep-UV Raman imaging spectrometer operating with an excitation wavelength of 228 nm. The designed system will provide the ability to detect explosives (both traditional military explosives and home-made explosives) from standoff distances of 1-10 meters with an interrogation area of 1 mm x 1 mm to 200 mm x 200 mm. This excitation wavelength provides resonant enhancement of many common explosives, no background fluorescence, and an enhanced cross-section due to the inverse wavelength scaling of Raman scattering. A coded-aperture spectrograph combined with compressive imaging algorithms will allow for wide-area interrogation with fast acquisition rates. Coded-aperture spectral imaging exploits the compressibility of hyperspectral data-cubes to greatly reduce the amount of acquired data needed to interrogate an area. The resultant systems are able to cover wider areas much faster than traditional push-broom and tunable filter systems. The full system design will be presented along with initial data from the instrument. Estimates for area scanning rates and chemical sensitivity will be presented. The system components include a solid-state deep-UV laser operating at 228 nm, a spectrograph consisting of well-corrected refractive imaging optics and a reflective grating, an intensified solar-blind CCD camera, and a high-efficiency collection optic. © 2012 SPIE.}, Doi = {10.1117/12.919292}, Key = {fds326018} } @article{fds326019, Author = {Knobel, RB and Guenther, BD and Rice, HE}, Title = {Thermoregulation and thermography in neonatal physiology and disease.}, Journal = {Biological Research For Nursing}, Volume = {13}, Number = {3}, Pages = {274-282}, Year = {2011}, Month = {July}, url = {http://dx.doi.org/10.1177/1099800411403467}, Abstract = {INTRODUCTION: Infrared thermal imaging, or thermography, is a technique used to measure body surface temperature in the study of thermoregulation. Researchers are beginning to use this novel methodology to study cancer, peripheral vascular disease, and wound management. METHODS: The authors tested the feasibility of using an FLIR SC640 uncooled, infrared camera to measure body temperature in neonates housed in heated, humid incubators. The authors examined thermograms to analyze distributions between central and peripheral body temperature in extremely low birth weight infants. The authors have also used this technology to examine the relationship between body temperature and development of necrotizing enterocolitis in premature infants. RESULTS: Handheld, uncooled, infrared cameras are easy to use and produce high-quality thermograms that can be visualized in grayscale or color palettes to enhance qualitative and quantitative analyses. CONCLUSION: Future research will benefit from the use of this noninvasive, inexpensive measurement tool. Nurse researchers can use this methodology in adult and infant populations to study temperature differentials present in pathological conditions.}, Doi = {10.1177/1099800411403467}, Key = {fds326019} } @article{fds326020, Author = {Kittle, D and Holshouser, B and Slater, JM and Guenther, BD and Pitsianis, NP and Pearlstein, RD}, Title = {Technical note: rapid prototyping of 3D grid arrays for image guided therapy quality assurance.}, Journal = {Medical physics}, Volume = {35}, Number = {12}, Pages = {5708-5712}, Year = {2008}, Month = {December}, url = {http://dx.doi.org/10.1118/1.3006198}, Abstract = {Three dimensional grid phantoms offer a number of advantages for measuring imaging related spatial inaccuracies for image guided surgery and radiotherapy. The authors examined the use of rapid prototyping technology for directly fabricating 3D grid phantoms from CAD drawings. We tested three different fabrication process materials, photopolymer jet with acrylic resin (PJ/AR), selective laser sintering with polyamide (SLS/P), and fused deposition modeling with acrylonitrile butadiene styrene (FDM/ABS). The test objects consisted of rectangular arrays of control points formed by the intersections of posts and struts (2 mm rectangular cross section) and spaced 8 mm apart in the x, y, and z directions. The PJ/AR phantom expanded after immersion in water which resulted in permanent warping of the structure. The surface of the FDM/ABS grid exhibited a regular pattern of depressions and ridges from the extrusion process. SLS/P showed the best combination of build accuracy, surface finish, and stability. Based on these findings, a grid phantom for assessing machine-dependent and frame-induced MR spatial distortions was fabricated to be used for quality assurance in stereotactic neurosurgical and radiotherapy procedures. The spatial uniformity of the SLS/P grid control point array was determined by CT imaging (0.6 x 0.6 x 0.625 mm3 resolution) and found suitable for the application, with over 97.5% of the control points located within 0.3 mm of the position specified in CAD drawing and none of the points off by more than 0.4 mm. Rapid prototyping is a flexible and cost effective alternative for development of customized grid phantoms for medical physics quality assurance.}, Doi = {10.1118/1.3006198}, Key = {fds326020} } @article{fds326021, Author = {Katz, LM and Nauriyal, V and Nagaraj, S and Finch, A and Pearlstein, K and Szymanowski, A and Sproule, C and Rich, PB and Guenther, BD and Pearlstein, RD}, Title = {Infrared imaging of trauma patients for detection of acute compartment syndrome of the leg.}, Journal = {Critical Care Medicine}, Volume = {36}, Number = {6}, Pages = {1756-1761}, Year = {2008}, Month = {June}, url = {http://dx.doi.org/10.1097/CCM.0b013e318174d800}, Abstract = {OBJECTIVE: Early compartment syndrome is difficult to diagnose, and a delay in the diagnosis can result in amputation or death. Our objective was to explore the potential of infrared imaging, a portable and noninvasive technology, for detecting compartment syndrome in the legs of patients with multiple trauma. We hypothesized that development of compartment syndrome is associated with a reduction in surface temperature in the involved leg and that the temperature reduction can be detected by infrared imaging. DESIGN: Observational clinical study. SETTING: Level I trauma center between July 2006 and July 2007. PATIENTS: Trauma patients presenting to the emergency department. INTERVENTIONS: Average temperature of the anterior surface of the proximal and distal region of each leg was measured in the emergency department with a radiometrically calibrated, 320 x 240, uncooled microbolometer infrared camera. MEASUREMENTS AND MAIN RESULTS: The difference in surface temperature between the thigh and foot regions (thigh-foot index) of the legs in trauma patients was determined by investigators blinded to injury pattern using thermographic image analysis software. The diagnosis of compartment syndrome was made intraoperatively. Thermographic images from 164 patients were analyzed. Eleven patients developed compartment syndrome, and four of those patients had bilateral compartment syndrome. Legs that developed compartment syndrome had a greater difference in proximal vs. distal surface temperature (8.80 +/- 2.05 degrees C) vs. legs without compartment syndrome (1.22 +/- 0.88 degrees C) (analysis of variance p < .01). Patients who developed unilateral compartment syndrome had a greater proximal vs. distal temperature difference in the leg with (8.57 +/- 2.37 degrees C) vs. the contralateral leg without (1.80 +/- 1.60 degrees C) development of compartment syndrome (analysis of variance p < .01). CONCLUSIONS: Infrared imaging detected a difference in surface temperature between the proximal and distal leg of patients who developed compartment syndrome. This technology holds promise as a supportive tool for the early detection of acute compartment syndrome in trauma patients.}, Doi = {10.1097/CCM.0b013e318174d800}, Key = {fds326021} } @article{fds326022, Author = {Fernandez, C and Lim, S and Guenther, BD and Brady, DJ and McCain, ST}, Title = {High-throughput, multiplex aperture-coded raman spectrometer for biomedical diagnostics}, Journal = {Biomedical Optics, BIOMED 2008}, Pages = {BTuF15}, Year = {2008}, Abstract = {Over the past couple of years, we have developed an aperture coded Raman spectrometer whose performance is optimized for extended, incoherent sources. We describe results conveying the potential for in vivo biomedical diagnostics. ©2007 Optical Society of America.}, Key = {fds326022} } @article{fds326023, Author = {Fang, J-S and Hao, Q and Brady, DJ and Guenther, BD and Hsu, KY}, Title = {A pyroelectric infrared biometric system for real-time walker recognition by use of a maximum likelihood principal components estimation (MLPCE) method}, Journal = {Optics express}, Volume = {15}, Number = {6}, Pages = {3271-3284}, Year = {2007}, url = {http://dx.doi.org/10.1364/OE.15.003271}, Abstract = {This paper presents a novel biometric system for real-time walker recognition using a pyroelectric infrared sensor, a Fresnel lens array and signal processing based on the linear regression of sensor signal spectra. In the model training stage, the maximum likelihood principal components estimation (MLPCE) method is utilized to obtain the regression vector for each registered human subject. Receiver operating characteristic (ROC) curves are also investigated to select a suitable threshold for maximizing subject recognition rate. The experimental results demonstrate the effectiveness of the proposed pyroelectric sensor system in recognizing registered subjects and rejecting unknown subjects. © 2007 Optical Society of America.}, Doi = {10.1364/OE.15.003271}, Key = {fds326023} } @article{fds326024, Author = {Fernandez, C and Guenther, BD and Gehm, ME and Brady, DJ and Sullivan, ME}, Title = {Longwave infrared (LWIR) coded aperture dispersive spectrometer}, Journal = {Optics express}, Volume = {15}, Number = {9}, Pages = {5742-5753}, Year = {2007}, url = {http://dx.doi.org/10.1364/OE.15.005742}, Abstract = {We describe a static aperture-coded, dispersive longwave infrared (LWIR) spectrometer that uses a microbolometer array at the detector plane. The two-dimensional aperture code is based on a row-doubled Hadamard mask with transmissive and opaque openings. The independent column code nature of the matrix makes for a mathematically well-defined pattern that spatially and spectrally maps the source information to the detector plane. Post-processing techniques on the data provide spectral estimates of the source. Comparative experimental results between a slit and coded aperture for emission spectroscopy from a CO2 laser are demonstrated. © 2007 Optical Society of America.}, Doi = {10.1364/OE.15.005742}, Key = {fds326024} } @article{fds246629, Author = {Burchett, J and Shankar, M and Hamza, AB and Guenther, BD and Pitsianis, N and Brady, DJ}, Title = {Lightweight biometric detection system for human classification using pyroelectric infrared detectors.}, Journal = {Applied Optics}, Volume = {45}, Number = {13}, Pages = {3031-3037}, Year = {2006}, Month = {May}, ISSN = {0003-6935}, url = {http://www.ncbi.nlm.nih.gov/pubmed/16639451}, Abstract = {We use pyroelectric detectors that are differential in nature to detect motion in humans by their heat emissions. Coded Fresnel lens arrays create boundaries that help to localize humans in space as well as to classify the nature of their motion. We design and implement a low-cost biometric tracking system by using off-the-shelf components. We demonstrate two classification methods by using data gathered from sensor clusters of dual-element pyroelectric detectors with coded Fresnel lens arrays. We propose two algorithms for person identification, a more generalized spectral clustering method and a more rigorous example that uses principal component regression to perform a blind classification.}, Key = {fds246629} } @article{fds326025, Author = {Fernandez, C and Guenther, BD and Gehm, ME and Brady, DJ and Sullivan, ME}, Title = {Longwave infrared (LWIR) coded aperture dispersive spectrometer}, Journal = {Optics InfoBase Conference Papers}, Year = {2006}, Month = {January}, Abstract = {We describe a static aperture-coded, dispersive longwave infrared (LWIR) spectrometer that uses a microbolometer array as the detector plane. We present experimental results of absorption spectroscopy for a variety of sources. © 2006 Optical Society of America.}, Key = {fds326025} } @article{fds326026, Author = {Fernandez, C and Guenther, BD and Gehm, ME and Brady, DJ and Sullivan, ME}, Title = {Longwave infrared (LWIR) coded aperture dispersive spectrometer}, Journal = {Optics InfoBase Conference Papers}, Year = {2006}, Month = {January}, Abstract = {We describe a static aperture-coded, dispersive longwave infrared (LWIR) spectrometer that uses a microbolometer array as the detector plane. We present experimental results of absorption spectroscopy for a variety of sources. © 2006 Optical Society of America.}, Key = {fds326026} } @article{fds326027, Author = {Fernandez, C and Guenther, BD and Gehm, ME and Brady, DJ and Sullivan, ME}, Title = {Longwave infrared (LWIR) coded aperture dispersive spectrometer}, Journal = {Optics InfoBase Conference Papers}, Year = {2006}, Month = {January}, Abstract = {We describe a static aperture-coded, dispersive longwave infrared (LWIR) spectrometer that uses a microbolometer array as the detector plane. We present experimental results of absorption spectroscopy for a variety of sources. © 2006 Optical Society of America.}, Key = {fds326027} } @article{fds326028, Author = {Fernandez, C and Guenther, BD and Gehm, ME and Brady, DJ and Sullivan, ME}, Title = {Longwave infrared (LWIR) coded aperture dispersive spectrometer}, Journal = {Optics InfoBase Conference Papers}, Year = {2006}, Month = {January}, Abstract = {We describe a static aperture-coded, dispersive longwave infrared (LWIR) spectrometer that uses a microbolometer array as the detector plane. We present experimental results of absorption spectroscopy for a variety of sources. © 2006 Optical Society of America.}, Key = {fds326028} } @article{9191646, Author = {Hao, Q and Brady, DJ and Guenther, BD and Burchett, JB and Shankar, M and Feller, S}, Title = {Human tracking with wireless distributed pyroelectric sensors}, Journal = {IEEE Sensors Journal}, Volume = {6}, Number = {6}, Pages = {1683-1695}, Year = {2006}, ISSN = {1530-437X}, url = {http://dx.doi.org/10.1109/JSEN.2006.884562}, Keywords = {Fresnel diffraction;lenses;pyroelectric detectors;sensor fusion;target tracking;}, Abstract = {This paper presents a wireless pyroelectric sensor system, composed of sensing modules (slaves), a synchronization and error rejection module (master), and a data fusion module (host), to perform human tracking. The computation workload distribution among slave, master, and host is investigated. The performances and costs of different signal-processing and target-tracking algorithms are discussed. A prototype system is described containing pyroelectric sensor modules that are able to detect the angular displacement of a moving thermal target. Fresnel lens arrays are used to modulate the sensor field of view. The sensor system has been used to track a single human target. © 2006 IEEE.}, Doi = {10.1109/JSEN.2006.884562}, Key = {9191646} } @article{9324013, Author = {Fang, J-S and Hao, Q and Brady, DJ and Guenther, BD and Hsu, KY}, Title = {Real-time human identification using a pyroelectric infrared detector array and hidden Markov models}, Journal = {Optics express}, Volume = {14}, Number = {15}, Pages = {6643-6658}, Year = {2006}, ISSN = {1094-4087}, url = {http://dx.doi.org/10.1364/OE.14.006643}, Keywords = {biometrics (access control);expectation-maximisation algorithm;feature extraction;hidden Markov models;image motion analysis;infrared detectors;lenses;optical arrays;pyroelectric detectors;}, Abstract = {This paper proposes a real-time human identification system using a pyroelectric infrared (PIR) detector array and hidden Markov models (HMMs). A PIR detector array with masked Fresnel lens arrays is used to generate digital sequential data that can represent a human motion feature. HMMs are trained to statistically model the motion features of individuals through an expectation-maximization (EM) learning process. Human subjects are recognized by evaluating a set of new feature data against the trained HMMs using the maximum-likelihood (ML) criterion. We have developed a prototype system to verify the proposed method. Sensor modules with different numbers of detectors and different sampling masks were tested to maximize the identification capability of the sensor system. © 2006 Optical Society of America.}, Doi = {10.1364/OE.14.006643}, Key = {9324013} } @article{fds326029, Author = {Shankar, M and Burchett, JB and Hao, Q and Guenther, BD and Brady, DJ}, Title = {Human-tracking systems using pyroelectric infrared detectors}, Journal = {Optical Engineering}, Volume = {45}, Number = {10}, Year = {2006}, url = {http://dx.doi.org/10.1117/1.2360948}, Abstract = {We design and develop a low-cost pyroelectric detector-based IR motion-tracking system. We study the characteristics of the detector and the Fresnel lenses that are used to modulate the visibility of the detectors. We build sensor clusters in different configurations and demonstrate their use for human motion tracking. © 2006 Society of Photo-Optical Instrumentation Engineers.}, Doi = {10.1117/1.2360948}, Key = {fds326029} } @article{fds326030, Author = {Fang, J-S and Hao, Q and Brady, DJ and Shankar, M and Guenther, BD and Pitsianis, NP and Hsu, KY}, Title = {Path-dependent human identification using a pyroelectric infrared sensor and Fresnel lens arrays}, Journal = {Optics express}, Volume = {14}, Number = {2}, Pages = {609-624}, Year = {2006}, url = {http://dx.doi.org/10.1364/OPEX.14.000609}, Abstract = {This paper presents a design and development of a low power consumption, and low cost, human identification system using a pyroelectric infrared (PIR) sensor whose visibility is modulated by a Fresnel lens array. The optimal element number of the lens array for the identification system was investigated and the experimental results suggest that the lens array with more elements can yield a better performance in terms of identification and false alarm rates. The other parameters of the system configuration such as the height of sensor location and sensor-to-object distance were also studied to improve spectral distinctions among sensory data of human objects. The identification process consists of two parts: training and testing. For the data training, we employed a principal components regression (PCR) method to cluster data with respect to different registered objects at different speed levels. The feature data of different objects walking along the same path in training yet at random speeds are then tested against the pre-trained clusters to decide whether the target is registered, and which member of the registered group it is. © 2006 Optical Society of America.}, Doi = {10.1364/OPEX.14.000609}, Key = {fds326030} } @article{8643962, Author = {Zheng, Y and Brady, DJ and Sullivan, ME and Guenther, BD}, Title = {Fiber-optic localization by geometric space coding with a two-dimensional gray code.}, Journal = {Applied Optics}, Volume = {44}, Number = {20}, Pages = {4306-4314}, Year = {2005}, Month = {July}, ISSN = {0003-6935}, url = {http://www.ncbi.nlm.nih.gov/pubmed/16045218}, Keywords = {binary codes;fibre optic sensors;Gray codes;image sensors;optical tracking;}, Abstract = {With the objective of monitoring motion within a room, we segment the two-dimensional (2D) floor space into discrete cells and encode each cell with a binary code word generated by a fiber. We design a set of k-neighbor-local codes to localize an extended object and, particularly when k = 2, employ a 2D gray code to localize a human by tracking his or her footsteps. Methods for implementing the codes in a fiber web are discussed, and we demonstrate the experimental result with the fiber mat. The observed system performance confirms the theoretical analysis. The space coding technique is a promising low-cost candidate not only for human tracking but also for other applications such as human gait analysis.}, Key = {8643962} } @article{fds326198, Author = {Guenther, BD and Jopson, B and Koshel, RJ and Paldus, B}, Title = {Optics in 2005}, Journal = {Optics & Photonics News}, Volume = {16}, Number = {12 SPEC. ISS.}, Pages = {14}, Year = {2005}, Month = {January}, url = {http://dx.doi.org/10.1364/OPN.16.12.000014}, Doi = {10.1364/OPN.16.12.000014}, Key = {fds326198} } @article{fds326031, Author = {Shankar, M and Burchett, JB and Feller, SD and Guenther, BD and Brady, DJ}, Title = {Human motion tracking system using coded Fresnel lens arrays}, Journal = {Optics InfoBase Conference Papers}, Year = {2005}, Month = {January}, Abstract = {We have designed and developed a low-cost human motion tracking system using pyroelectric detectors and coded Fresnel lens arrays. We have deployed sensor clusters implementing an 8x8 Hadamard code variant and will demonstrate motion tracking. © 2005 Optical Society of America.}, Key = {fds326031} } @article{fds326032, Author = {Peters, AE and Gehm, ME and Guenther, BD and Brady, DJ}, Title = {Multiplex design for high-performance microspectrometers}, Journal = {Optics InfoBase Conference Papers}, Year = {2005}, Month = {January}, Abstract = {The volume of spectrometers can be drastically reduced through the use of multiplex measurement. Reductions of 3-5 orders of magnitude are possible. This has the potential to drastically effect manufacturing and deployment costs. ©2005 Optical Society of America.}, Key = {fds326032} } @article{fds326033, Author = {Shankar, M and Jones, DB and Swagart, RG and Burchett, JB and Guenther, BD and Feller, SD and Brady, DJ}, Title = {Large area pyroelectric motion tracking system}, Journal = {Optics InfoBase Conference Papers}, Year = {2005}, Month = {January}, Abstract = {Simple pyroelectric detectors and structured apertures are used to monitor motion in an area and report location and velocity of objects moving through the monitored area. © 2005 OSA/COSI 2005.}, Key = {fds326033} } @article{fds326034, Author = {Feller, SD and Burchett, JB and Hao, Q and Fang, JS and Shankar, M and Guenther, BD and Brady, DJ}, Title = {Human characterization and tracking using pyroelectric sensors}, Journal = {Optics InfoBase Conference Papers}, Year = {2005}, Month = {January}, Abstract = {A network of common pyroelectric motion sensors that can track and identify human targets has been developed using low-cost, commercially available components. Significantly cheaper than deploying infrared imag- ing systems and considerably more advanced than typical motion sensing systems, this system consists of a small number of sensor nodes distributed across a medium sized room. Each node contain up to eight pyroelectric detectors and provides limited computation and communication capabil- ities. These detectors use structured lenslets to extract frequency com- ponents of targets for classification and the location and orientation of the sensors is used to track targets as they move through the space. This system has demonstrated multiple target tracking and the ability to dif- ferentiate between multiple people. © 2005 OSA/OSHS 2005.}, Key = {fds326034} } @article{fds44507, Author = {B.D. Guenther}, Title = {Diffraction}, Volume = {2}, Booktitle = {Encyclopedia of Modern Optics}, Publisher = {Elsevier}, Editor = {B.D. Guenther,Editor in Chief}, Year = {2005}, Key = {fds44507} } @article{fds44508, Author = {J.S. Murday and B.D. Guenther and C.G. Lau and C.R.K. Marrian and J.C. Paxik and G.S. Pomrenke}, Title = {Overview of the Nanoscale Science and Technology Program in teh Department of Defense}, Series = {ACS Symposium 891}, Pages = {2-14}, Booktitle = {Defense Applications of Nanomaterials}, Publisher = {American Chemicall Society}, Editor = {A.W. Miziolek and S.P. Karna and J.M. Mauro and R.A. Vaia}, Year = {2005}, Key = {fds44508} } @article{05429421140, Author = {Cull, EC and Gehm, ME and McCain, ST and Guenther, BD and Brady, DJ}, Title = {Multimodal optical spectrometers for remote chemical detection}, Journal = {Proceedings of SPIE - The International Society for Optical Engineering}, Volume = {5778}, Number = {PART I}, Pages = {376-382}, Address = {Orlando, FL, United States}, Year = {2005}, ISSN = {0277-786X}, url = {http://dx.doi.org/10.1117/12.606574}, Keywords = {Optical systems;Remote sensing;Raman scattering;Throughput;Spectrum analyzers;}, Abstract = {We have developed a class of aperture coding schemes for Remote Raman Spectrometers (RRS) that remove the traditional trade-off between throughput and spectral resolution. As a result, the size of the remote interrogation region can be driven by operational, rather than optical considerations. We present theoretical arguments on the performance of these codes and present data from where we have utilized these codes in other spectroscopy efforts.}, Doi = {10.1117/12.606574}, Key = {05429421140} } @article{9008262, Author = {Shankar, M and Burchett, J and Feller, SD and Jones, B and Swagart, R and Guenther, BD and Brady, DJ}, Title = {Biometric tracking with coded pyroelectric sensor clusters}, Journal = {Proc. SPIE - Int. Soc. Opt. Eng. (USA)}, Volume = {5796}, Number = {1}, Pages = {181-192}, Address = {Orlando, FL, USA}, Year = {2005}, url = {http://dx.doi.org/10.1117/12.606557}, Keywords = {biometrics (access control);image classification;infrared imaging;lenses;motion estimation;optical arrays;optical sensors;pyroelectric detectors;}, Abstract = {Human bodies are very good heat sources with peak emission wavelength of about 9 μm. We use pyroelectric detectors that are differential in nature to detect human motion by their heat emissions. Coded Fresnel lens arrays create boundaries in space which helps to localize the human motion as well as classification. We design and implement a low-cost biometric tracking system using off-the-shelf components. We demonstrate tracking and classification using sensor clusters of dual-element pyroelectric detectors with coded Fresnel lens arrays}, Doi = {10.1117/12.606557}, Key = {9008262} } @article{06109742883, Author = {Cull, EC and Gehm, ME and Guenther, BD and Brady, DJ}, Title = {Standoff raman spectroscopy system for remote chemical detection}, Journal = {Proceedings of SPIE - The International Society for Optical Engineering}, Volume = {5994}, Pages = {59940}, Address = {Boston, MA, United States}, Year = {2005}, ISSN = {0277-786X}, url = {http://dx.doi.org/10.1117/12.626170}, Keywords = {Remote sensing;Data reduction;Throughput;}, Abstract = {We have developed a class of aperture coding schemes for Remote Raman Spectrometers (RRS) that remove the traditional trade-off between throughput and spectral resolution. As a result, the size of the remote interrogation region can be driven by operational, rather than optical considerations. In this paper we present the design of our coded-aperture standoff spectroscopy system as well as experimental data collected while making remote measurements.}, Doi = {10.1117/12.626170}, Key = {06109742883} } @article{fds326199, Author = {Guenther, BD}, Title = {Optics in 2003}, Journal = {Optics & Photonics News}, Volume = {14}, Number = {12}, Pages = {15}, Year = {2003}, Month = {January}, Key = {fds326199} } @article{fds44505, Author = {B.D. Guenther and Chair}, Title = {Combat Hybrid Power System component Technologies” Committee on Assessment of Combat Hybrid Power Systems}, Booktitle = {National Materials Advisory Board, National Research Council}, Publisher = {National Academies Press}, Year = {2002}, Key = {fds44505} } @article{fds246630, Author = {Guenther, BD and Weller, H and Godwin, JL}, Title = {Report of the Bioterrorism Workshop}, Journal = {Journal of Microbiological Methods}, Volume = {51}, Pages = {247-254}, Year = {2002}, Key = {fds246630} } @article{fds246632, Author = {Demers, JR and Goyette, TM and Ferrio, KB and Everitt, HO and Guenther, BD and De Lucia and FC}, Title = {Spectral purity and sources of noise in femtosecond-demodulation terahertz sources driven by Ti : sapphire mode-locked lasers}, Journal = {IEEE Journal of Quantum Electronics}, Volume = {37}, Number = {4}, Pages = {595-605}, Year = {2001}, Month = {April}, ISSN = {0018-9197}, url = {http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000167766000015&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=47d3190e77e5a3a53558812f597b0b92}, Doi = {10.1109/3.914410}, Key = {fds246632} } @article{01246539807, Author = {Demers, J.R. and Goyette, T.M. and Ferrio, K.B. and Everitt, H.O. and Guenther, B.D. and De Lucia and F.C.}, Title = {Spectral purity and sources of noise in femtosecond-demodulation terahertz sources driven by Ti:sapphire mode-locked lasers}, Journal = {IEEE Journal of Quantum Electronics}, Volume = {37}, Number = {4}, Pages = {595 - 605}, Year = {2001}, url = {http://dx.doi.org/10.1109/3.914410}, Keywords = {Light modulation;Ultrafast phenomena;Laser mode locking;Spectrum analysis;Frequencies;Timing jitter;Pumping (laser);}, Abstract = {Direct measurements of the spectral purity in terahertz femtosecond-demodulation sources are reported and compared to theory. Because these sources operate at very high harmonics ( [similar to] 10<sup>2</sup> - 10<sup>4</sup>) of the mode-lock frequency, a high spectral purity source is very dependent on a low-jitter femtosecond laser. Conversely, the spectral content of the terahertz sources provides detailed information about timing jitter and stringent tests of models used to describe the jitter. We find that both the behavior of the central core, and the noise skirts of the power spectrum of our sources, can be quantitatively related to measured ripple and continuum amplitude noise on the Ar<sup>+</sup> pump laser by use of modulation theory.}, Key = {01246539807} } @article{fds44503, Author = {B.D. Guenther and H. Weller and J.L. Godwin}, Title = {A Search for Nuclear Isotopes for Use in a Nuclear Battery}, Journal = {AIAA J. Prop & Power}, Volume = {17}, Number = {3}, Year = {2001}, Key = {fds44503} } @article{01306591342, Author = {Guenther, BD and Weller, HR and Godwin, JL}, Title = {Search for nuclear isotopes for use in a nuclear battery}, Journal = {Journal of Propulsion and Power}, Volume = {17}, Number = {3}, Pages = {540-546}, Year = {2001}, ISSN = {0748-4658}, url = {http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000168804600008&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=47d3190e77e5a3a53558812f597b0b92}, Keywords = {Nuclear batteries;Thermoelectricity;Electric generators;Electrons;Electron energy levels;Electron transitions;Gamma rays;Backscattering;}, Abstract = {Performance of a radioisotopic thermoelectric generator for a human-portable energy source is discussed. The design of thermoelectric generators is not considered. Instead desirable characteristics of the radioisotope are used to search for reasonable candidates with a half-life measured in weeks and generating radiation that could easily be shielded. Because radioisotopes with short half-lives would have limited shelf-lives, a search was undertaken to discover if isomers with different decay paths existed with characteristics that would lead to a useful energy generator design. The results indicate several interesting cases for energy storage in radioactive isotopes. Two of the most interesting cases uncovered were <sup>121</sup>Te and <sup>254</sup>Es. However, intermediate levels that could be used to connect the various nuclear energy levels are not currently known. Measurements of transition rates that can be stimulated between the desired levels are also needed to determine the practicality of this concept. Such research is now possible using the intense gamma beam that can be produced using free-electron laser light backscattered from relativistic electrons.}, Doi = {10.2514/2.5809}, Key = {01306591342} } @article{fds326200, Author = {Guenther, BD}, Title = {Second annual OSA Executive Forum: Photonics and telecommunications - The tidal wave of the new millenium}, Journal = {Optics & Photonics News}, Volume = {10}, Number = {10}, Pages = {14-18}, Year = {1999}, Month = {January}, Key = {fds326200} } @article{6520139, Author = {Ferrio, K.B. and Herlocker, J.A. and Hendrickx, E. and Guenther, B.D. and Peyghambarian, N. and Kippelen, B. and Mery, S.}, Title = {Charge transport and chromophore orientation in a new photorefractive polymer composite with response-time in the millisecond-regime}, Journal = {Technical Digest. Summaries of papers presented at the Conference on Lasers and Electro-Optics. Postconference Edition. CLEO '99. Conference on Lasers and Electro-Optics (IEEE Cat. No.99CH37013)}, Pages = {510 - 11}, Address = {Baltimore, MD, USA}, Year = {1999}, url = {http://dx.doi.org/10.1109/CLEO.1999.834518}, Keywords = {carrier mobility;filled polymers;optical modulation;optical polymers;photoconducting materials;photorefractive materials;}, Abstract = {Summary form only given. Since the first observation of photorefractivity in a polymer composite, applications to information-processing and dynamic holography have spurred rapid development. A critical step was the realization that index-modulation is enhanced by reorientation of birefringent chromophores in composites with low glass-transition temperatures, T<sub>g</sub>. Now attention has turned to understanding and improving response-times. A composite with a 4-ms component has been reported recently, with persuasive evidence that photoconductivity limits speed. We report an even faster 1.8-ms component in a very different composite a fluorinated cyanotolane chromophore}, Key = {6520139} } @article{00025024609, Author = {Peyghambarian, N. and Ferrio, K.B. and Herlocker, J.A. and Handrickx, E. and Guenther, B.D. and Mery, S. and Zhang, Y. and Kippelen, B.}, Title = {Photorefractive polymers with high speed}, Journal = {Materials Research Society Symposium - Proceedings}, Volume = {561}, Pages = {131 - 139}, Address = {San Francisco, CA, USA}, Year = {1999}, Keywords = {Photorefractive materials;Diffraction gratings;Nonlinear optics;Four wave mixing;Optical devices;Holograms;}, Abstract = {Rapid progress in photorefractive polymers includes new materials with improved response rates. We briefly review recent developments in this rapidly evolving area and report grating formation with a 2-millisecond time-constant, the fastest reported to date in any photorefractive polymer.}, Key = {00025024609} } @article{6400670, Author = {Khoo, IC and Shih, M-Y and Wood, MV and Guenther, BD and Chen, PH and Simoni, F and Slussarenko, SS and Francescangeli, O and Lucchetti, L}, Title = {Dye-doped photorefractive liquid crystals for dynamic and storage holographic grating formation and spatial light modulation}, Journal = {Proc. IEEE (USA)}, Volume = {87}, Number = {11}, Pages = {1897-1911}, Year = {1999}, url = {http://dx.doi.org/10.1109/5.796353}, Keywords = {dyes;holographic gratings;holographic storage;liquid crystal devices;multiwave mixing;nematic liquid crystals;optical films;refractive index;space charge;spatial light modulators;}, Abstract = {The basic mechanisms of photo-induced space charge field formation, director axis re-orientation, and refractive index changes in fullerene C60- and dye-doped nematic liquid crystals films are presented. In particular, in aligned methyl-red-doped nematic liquid crystal film, we observe a nonlinear index change coefficient as high as 10 cm2/W, associated with purely optically induced liquid crystal director axis re-orientation. Experimental observations of dynamic and high-resolution storage holographic grating formation, two beam coupling with gain of nearly 3000 cm-1, optical limiting action at nanowatt cw laser power, and incoherent-coherent image conversion at μW/cm2 light intensity level are discussed}, Doi = {10.1109/5.796353}, Key = {6400670} } @article{99104859733, Author = {Herlocker, JA and Ferrio, KB and Hendrickx, E and Guenther, BD and Mery, S and Kippelen, B and Peyghambarian, N}, Title = {Observation of 4-ms response-time in a photorefractive polymer}, Journal = {Proceedings of SPIE - The International Society for Optical Engineering}, Volume = {3623}, Pages = {168-174}, Address = {San Jose, CA, USA}, Year = {1999}, url = {http://dx.doi.org/10.1117/12.348395}, Keywords = {Organic polymers;Diffraction gratings;Ellipsometry;Optical properties;Electric field effects;}, Abstract = {Efficient photorefractive polymers hold great potential for optical data processing and storage and so have been a topic of intense investigations in recent years. Materials with nearly 100% diffraction efficiencies have been developed, but these have been generally characterized by much slower responses than their less efficient inorganic counterparts. In this report, we describe a 4-ms initial rise-time using a visible-transparent chromophore in a PVK-based polymer of Tg = 39°C for 48-V/µm bias projected along the grating vector and 250-m W/cm2 writing beams. This fast component consistently accounts for 90% of the steady-state response and is analyzed as a function of bias field. We also present transient ellipsometry measurements of an orientational response significantly faster than the grating development, suggesting that chromophore alignment speed does not limit transient grating formation. We describe the role of such underlying property measurements in understanding photorefractive transient behavior, and prospects for further improvements.}, Doi = {10.1117/12.348395}, Key = {99104859733} } @article{99104821307, Author = {Herlocker, JA and Ferrio, KB and Hendrickx, E and Guenther, BD and Mery, S and Kippelen, B and Peyghambarian, N}, Title = {Direct observation of orientation limit in a fast photorefractive polymer composite}, Journal = {Applied Physics Letters}, Volume = {74}, Number = {16}, Pages = {2253-2255}, Year = {1999}, url = {http://dx.doi.org/10.1063/1.123816}, Keywords = {Vinyl resins;Fluorine containing polymers;Chromophores;Four wave mixing;Photosensitizers;Refractive index;Ellipsometry;Diffraction gratings;Birefringence;Light absorption;}, Abstract = {The photorefractivity and chromophore orientation in polymer composites were studied. The composites were made from poly-N-vinylcarbazole, N-ethylcarbazole, and (2,4,7-trinitro-9-fluorenylidene)malonodinitrile with a fluorinated cyano-tolane chromophore. The transient photorefractive response in four-wave mixing (FWM) and two-beam coupling (TBC) was measured. Transient FWM revealed a photorefractive response dominated by a fast time constant of 4 ms, while transient ellipsometry revealed an orientational response of only 490 μs.}, Doi = {10.1063/1.123816}, Key = {99104821307} } @article{6397883, Author = {Hendrickx, E and Guenther, BD and Zhang, Y and Wang, JF and Staub, K and Zhang, Q and Marder, SR and Kippelen, B and Peyghambarian, N}, Title = {Ellipsometric determination of the electric-field-induced birefringence of photorefractive dyes in a liquid carbazole derivative}, Journal = {Chem. Phys. (Netherlands)}, Volume = {245}, Number = {1-3}, Pages = {407-415}, Year = {1999}, url = {http://dx.doi.org/10.1016/S0301-0104(99)00049-X}, Keywords = {birefringence;dyes;ellipsometry;organic compounds;photorefractive materials;polarisability;}, Abstract = {We have used ellipsometric measurements on solutions of 2-dihexylamino-7-dicyanomethylidene-3,4,4a,5,6-pentahydronaphthalene and related polyenes in liquid 9-(2'-ethylhexyl)carbazole to measure the electric-field-induced birefringence at wavelengths of 690 nm and 830 nm. This electric-field-induced birefringence is related to the product of dipole moment squared and the polarizability anisotropy, μ2Δα, and to a large extent determines the dye's photorefractive figure-of-merit (FOM). We show that μ2Δα increases with the conjugation length and report one of the highest μ2Δα values observed so far}, Doi = {10.1016/S0301-0104(99)00049-X}, Key = {6397883} } @article{99104830904, Author = {Peyghambarian, N and Ferrio, KB and Herlocker, JA and Hendrickx, E and Guenther, BD and Kippelen, B and Mery, S}, Title = {Photorefractive polymers with video-rate performance}, Journal = {Proceedings of SPIE - The International Society for Optical Engineering}, Volume = {3749}, Pages = {336-337}, Address = {San Francisco, CA, USA}, Year = {1999}, url = {http://dx.doi.org/10.1117/12.354773}, Keywords = {Vinyl resins;Chromophores;Birefringence;Photoconductivity;Transparency;Photosensitizers;Diffraction gratings;Electric field effects;Ellipsometry;Electric potential;}, Abstract = {The introduction of birefringent chromophores with ground-state dipole moments into a photoconductive polymer host has provided the design flexibility to improve both dynamic range and speed. From the diffraction efficiency and Kogelnik's theory of thick gratings, it exhibits a dominant response time of approximately 2 ms for the underlying index-modulation with an additional slow component of approximately 1 ms and may support applications requiring video-rates. The orientational mobility of the chromophores is not limiting the response of the composite and kiloherts-regime responses may be achievable with improved photoconductivity.}, Doi = {10.1117/12.354773}, Key = {99104830904} } @article{98084340144, Author = {Khoo, I.C. and Slussarenko, S. and Guenther, B.D. and Shih, Min-Yi and Chen, P. and Wood, W.V.}, Title = {Optical nonlinear index coefficient of over 6 cm2/W in dye-doped nematic liquid crystals}, Journal = {Conference on Lasers and Electro-Optics Europe - Technical Digest}, Pages = {215 - 216}, Address = {San Francisco, CA, USA}, Year = {1998}, url = {http://dx.doi.org/10.1109/CLEO.1998.676075}, Keywords = {Nematic liquid crystals;Optical materials;Refractive index;Diffraction gratings;Dye lasers;Thick films;}, Abstract = {The observation of an extraordinarily large purely optically induced refractive index change mechanism in methyl-red dye-doped nematic liquid crystal film is reported. A refractive index change coefficient of over 6 cm<sup>2</sup>/W was obtained. Visually observable self-diffraction and holographic grating diffraction can be generated with optical intensity as low as 40 μW/cm<sup>2</sup>. The response times are measured to be in the milliseconds regime.}, Key = {98084340144} } @article{5856220, Author = {Khoo, I.C. and Wood, M.V. and Guenther, B.D.}, Title = {Liquid crystals for fast infrared laser switching and optical limiting application}, Journal = {Materials for Optical Limiting II. Symposium}, Pages = {229 - 34}, Address = {San Franicso, CA, USA}, Year = {1998}, Keywords = {electro-optical switches;liquid crystal devices;molecular reorientation;multiwave mixing;nematic liquid crystals;nonlinear optics;}, Abstract = {We present the results of several experimental studies of infrared [IR] nonlinear optical responses of aligned nematic liquid crystals, including laser induced molecular reorientation, density-, thermal- and order paramter-changes, optical wave mixing, beam amplification, and interface switching effects. Using lasers in the near-IR [1.55 μm], mid-IR [5 μm] and IR [10.6 μm] spectral regime, the potentials for nonlinear optical applications with CW, millisecond to microsecond lasers are explored}, Key = {5856220} } @article{5856221, Author = {Khoo, I.C. and Wood, M.V. and Guenther, B.D.}, Title = {Nonlinear optical fiber core materials for optical limiting application}, Journal = {Materials for Optical Limiting II. Symposium}, Pages = {241 - 7}, Address = {San Franicso, CA, USA}, Year = {1998}, Keywords = {arrays;high-speed optical techniques;liquid crystal devices;nonlinear optics;optical fibres;}, Abstract = {Several liquid phase liquid crystals and liquids are found to possess broadband nonlinear absorption characteristics suitable for optical limiting applications. Using these liquids as fiber waveguiding cores, we have developed fiber arrays that provide excellent limiting performance characteristics against frequency agile visible laser pulses in the nanosecond-picosecond time scale. These fiber arrays are compact, low cost/weight, and are capable of transmitting high quality images throughout the entire visible spectrum}, Key = {5856221} } @article{99024581921, Author = {Khoo, I.C. and Shih, M.Y. and Chen, Ph. and Wood, M. and Guenther, B.D.}, Title = {Nematic liquid crystal film with a nonlinear index coefficient of over 10 cm2/Watt and ms response speed}, Journal = {Conference Proceedings - Lasers and Electro-Optics Society Annual Meeting-LEOS}, Volume = {2}, Pages = {201 - 202}, Address = {Orlando, FL, USA}, Year = {1998}, url = {http://dx.doi.org/10.1109/LEOS.1998.739530}, Keywords = {Nematic liquid crystals;Birefringence;Electric potential;Refractive index;Electric space charge;Anisotropy;Dyes;Light modulators;Diffraction gratings;Nonlinear optics;Adaptive optics;}, Abstract = {Liquid crystals posses large birefringence spanning the visible to infrared spectral regime and large optical nonlinearities. One advantage of dye doped nematic liquid crystal (DDLC) over a commercial liquid crystal spatial light modulators (SLM) is the resolution capability. The resolution of DDLC can be over 200 lp/nm compared to commercial SLM's typical resolution capability of at most 40 lp/nm. Since many dyes exist that will cover a wide spectrum, these DDLC films are promising candidates for developing broadband optical modulators and limiters, adaptive optics and dynamic holographic optical devices and for wavelength or coherent-incoherent image conversion devices.}, Key = {99024581921} } @article{98084340364, Author = {Khoo, I.C. and Guenther, B.D. and Shih, Min-Yi and Chen, P.H. and Wood, M.V.}, Title = {Optical limiting of submicrowatt long-pulse cw lasers with extremely nonlinear nematic liquid crystal films}, Journal = {Conference on Lasers and Electro-Optics Europe - Technical Digest}, Pages = {374 - 375}, Address = {San Francisco, CA, USA}, Year = {1998}, url = {http://dx.doi.org/10.1109/CLEO.1998.676330}, Keywords = {Limiters;Nematic liquid crystals;Nonlinear optics;Focusing;Diffraction gratings;Light polarization;Light absorption;Band structure;Optical variables measurement;Refractive index;}, Abstract = {The feasibility of optical limiting with submicrowatt laser power at milliseconds speed is demonstrated. Because many dyes exist that will cover the entire visible spectrum, such dye-doped nematic films are highly promising candidates for application as very broadband optical limiters. These films can be easily integrated onto other optical limiting devices to fabricate devices that will provide protection against frequency agile picosecond cw lasers.}, Key = {98084340364} } @article{98074282885, Author = {Khoo, IC and Wood, MV and Guenther, BD and Shih, M-Y and Chen, PH}, Title = {Nonlinear absorption and optical limiting of laser pulses in a liquid-cored fiber array}, Journal = {Journal of the Optical Society of America B: Optical Physics}, Volume = {15}, Number = {5}, Pages = {1533-1540}, Year = {1998}, Keywords = {Light absorption;Optical fibers;Molecular structure;Molecules;Refractive index;Fullerenes;Liquid crystals;Laser pulses;Neodymium lasers;Numerical methods;}, Abstract = {A model for the nonlinear molecular photonic processes occurring in the fiber-core liquid molecules was developed. The model was used to analyze the nonlinear transmission of nanosecond and picosecond laser pulses through these fibers. In the picosecond regime, nonlinear absorptions play the dominant role, whereas in the nanosecond regime, thermal-density effects are further required for achieving comparable limiting performance characteristics. The thresholds and limited-clamped output from these fiber structures are below sensor damage levels.}, Key = {98074282885} } @article{6190962, Author = {Khoo, IC and Wood, MV and Chen, P and Shih, M-Y and Guenther, BD}, Title = {Novel liquid-cored fiber and liquid crystal film for sensor protection against visible ps-cw lasers}, Journal = {Proc. SPIE - Int. Soc. Opt. Eng. (USA)}, Volume = {3472}, Pages = {30-39}, Address = {San Diego, CA, USA}, Year = {1998}, url = {http://dx.doi.org/10.1117/12.326888}, Keywords = {high-speed optical techniques;laser beam effects;nematic liquid crystals;optical fibres;optical films;optical limiters;optical saturable absorption;optical self-focusing;optical sensors;radiation protection;two-photon processes;}, Abstract = {We have developed compact millimeter thick optical fiber arrays with nonlinear optical liquid guiding cores. These image transmitting fiber arrays are capable of passive optical limiting action against frequency agile short (picosecond-nanosecond) laser pulses in the visible spectrum. We present the results of further studies of their limiting performance. We also discuss how a recently discovered extraordinarily large nonlinear optical response of methyl-red doped nematic liquid crystal film may be employed for limiting action on longer pulse or cw lasers with nanowatt threshold power}, Doi = {10.1117/12.326888}, Key = {6190962} } @article{6508149, Author = {Khoo, IC and Guenther, BD and Slussarenko, S}, Title = {Photo-induced space charge fields, photo-voltaic, photorefractivity, and optical wave mixing in nematic liquid crystals}, Journal = {Mol. Cryst. Liq. Cryst. (Switzerland)}, Volume = {321}, Pages = {863-882}, Address = {Heppenheim an der Bergstrasse, Germany}, Year = {1998}, Keywords = {electro-optical effects;holographic gratings;holographic storage;multiwave mixing;nematic liquid crystals;photoconductivity;photorefractive effect;space charge;}, Abstract = {We present a detailed discussion of the fundamental mechanisms for recently observed nonlinear electro-optical wave mixing effects in nematic liquid crystal films. Experimental results on photoconductivity, photorefractive-like two beam coupling, beam amplification, self-diffraction, and storage holographic grating formation in dye- and fullerene C60 and C61 doped nematic films are presented along with a review of two- and four-wave mixing theories. Nematic liquid crystal films are shown to be potentially useful for adaptive and optical storage applications}, Key = {6508149} } @article{6216736, Author = {Khoo, IC and Wood, MV and Chen, P and Shih, M-Y and Guenther, BD}, Title = {Self-defocusing and optical limiting of nanoWatt cw laser and image processing at μ Watt/cm2 intensity with nematic liquid crystals}, Journal = {Proc. SPIE - Int. Soc. Opt. Eng. (USA)}, Volume = {3475}, Pages = {143-149}, Address = {San Diego, CA, USA}, Year = {1998}, url = {http://dx.doi.org/10.1117/12.326900}, Keywords = {image processing;liquid crystal devices;nematic liquid crystals;optical limiters;refractive index;spatial light modulators;}, Abstract = {Using nematic liquid crystal films doped with photocharge producing dyes, we have demonstrated the feasibility of optical limiting of long pulse-cw lasers at nanowatt power, and clamped transmission of ≪1 μJ. We also demonstration incoherent-coherent image conversion capability with optical intensity in the μWatt/cm2 level}, Doi = {10.1117/12.326900}, Key = {6216736} } @article{98034118987, Author = {Khoo, IC and Slussarenko, S and Guenther, BD and Shih, M-Y and Chen, P and Wood, WV}, Title = {Optically induced space-charge fields, dc voltage, and extraordinarily large nonlinearity in dye-doped nematic liquid crystals}, Journal = {Optics Letters}, Volume = {23}, Number = {4}, Pages = {253}, Year = {1998}, Key = {98034118987} } @article{5961991, Author = {Khoo, IC and Wood, MV and Guenther, BD and Shih, M-Y and Chen, PH and Chen, Z and Zhang, X}, Title = {Nonlinear optical liquid cored fiber array and liquid crystal film for ps-CW frequency agile laser optical limiting application}, Journal = {Optics Express}, Volume = {2}, Number = {12}, Year = {1998}, Keywords = {arrays;high-speed optical techniques;liquid films;nematic liquid crystals;nonlinear optics;optical fibres;organic compounds;}, Abstract = {The molecular nonlinear photonic absorption processes of two nonlinear fiber core liquids are discussed in the context of nonlinear propagation and optical limiting of short pulses, these fiber arrays are capable of limiting threshold and clamped output below 1 μJ for picosecond and nanosecond pulses. We also discuss the observation of perhaps the largest optical nonlinearity in some dye-doped nematic liquid crystal films. These films provide limiting action with a threshold power of 100 nWatt and limited transmission of ≪1 microJoule for ms-CW laser}, Key = {5961991} } @article{5831115, Author = {Guenther, BD and Khoo, IC}, Title = {Beam amplification and cleanup with two-and four-wave mixing in photorefractive nematic liquid crystal films}, Journal = {Proc. SPIE - Int. Soc. Opt. Eng. (USA)}, Volume = {3143}, Pages = {191-200}, Address = {San Diego, CA, USA}, Year = {1997}, Keywords = {adaptive optics;liquid crystal devices;multiwave mixing;nematic liquid crystals;optical crosstalk;optical films;photorefractive materials;}, Abstract = {Recent theoretical and experimental results have shown that the orientational photorefractive effect seen in doped nematic liquid crystal films gives rise to strong beam amplification effects without suffering from phase crosstalk. These effects, examined for both four and two wave mixing, are well suited for adaptive optics applications}, Key = {5831115} } @article{97093804540, Author = {Khoo, IC and Guenther, BD and Wood, MV and Chen, P and Shih, M-Y}, Title = {Coherent beam amplification with a photorefractive liquid crystal}, Journal = {Optics Letters}, Volume = {22}, Number = {16}, Pages = {1229-1231}, Year = {1997}, Keywords = {Light refraction;Nematic liquid crystals;Thin films;Fullerenes;Diffraction gratings;Laser applications;Four wave mixing;}, Abstract = {This report discusses the enhancement of the beam-coupling effect with the use of a more efficient photocharge-producing dopant such as fullerene C60 and a much larger effective applied dc field in thinner liquid-crystal films. More importantly, it is shown that the beam-amplification process is accompanied by negligible phase cross talk between pump and the signal beams similar to those observed in photorefractive crystals.}, Key = {97093804540} } @article{5831130, Author = {Khoo, IC and Wood, MV and Shih, M-Y and Guenther, BD and Chen, P}, Title = {Analytical modeling of nonlinear-and excited state-absorption and optical limiting in a liquid-cored fiber array}, Journal = {Proc. SPIE - Int. Soc. Opt. Eng. (USA)}, Volume = {3146}, Pages = {125-132}, Address = {San Diego, CA, USA}, Year = {1997}, Keywords = {excited states;high-speed optical techniques;image resolution;limiters;nonlinear optics;optical fibre communication;optical fibres;optical materials;visual communication;}, Abstract = {Recently observed optical limiting effects of nano-and pico-second laser pulses through a fiber array are analyzed using a model that accounts for various nonlinear and excited state absorption, and subsequent thermal and density effects occurring in the fiber guiding core materials. The nonlinear liquid cored-fiber arrays we have constructed are capable of low optical limiting threshold and clamped output, as well as high resolution image transmission}, Key = {5831130} } @article{97103894974, Author = {Ratches James and A and Walters, CP and Buser Rudolf and G and Guenther, BD}, Title = {Aided and automatic target recognition based upon sensory inputs from image forming systems}, Journal = {IEEE Transactions on Pattern Analysis and Machine Intelligence}, Volume = {19}, Number = {9}, Pages = {1004-1019}, Year = {1997}, url = {http://dx.doi.org/10.1109/34.615449}, Keywords = {Image sensors;Military applications;Algorithms;Sensor data fusion;Mathematical models;Signal to noise ratio;Data acquisition;Database systems;}, Abstract = {This paper systematically reviews 10 years of research that several Army Laboratories conducted in object recognition algorithms, processors, and evaluation techniques. In the military, object recognition is applied to the discrimination of military targets, ranging from human-aided to autonomous operations, and is called Automatic Target Recognition (ATR). The research described here has been concentrated in human-aided target recognition applications, but some attention has been paid to automatic processes. Definitions and performance metrics that have been developed are described along with performance data showing the present state-of-the-art. The effects of signal-to-noise and clutter parameters are indicated in the data. Multisensor fusion and model-based algorithms are discussed as the latest techniques under consideration by the military research community. The results demonstrate that useful performance can be achieved, and tools are evolving to understand and improve the performance under real-world conditions. The referenced research strongly indicates the need for the development of image science, as described in the paper, to support the theoretical underpinnings of ATR.}, Doi = {10.1109/34.615449}, Key = {97103894974} } @article{97013496365, Author = {Simoni, F. and Francescangeli, O. and Reznikov, Y. and Slussarenko, S. and Khoo, I.C. and Wood, M. and Guenther, B.D.}, Title = {Optical holographic grating formation in dye- and fullerene-doped liquid crystalline system}, Journal = {Conference Proceedings - Lasers and Electro-Optics Society Annual Meeting-LEOS}, Volume = {1}, Pages = {265 -}, Address = {Boston, MA, USA}, Year = {1996}, url = {http://dx.doi.org/10.1109/LEOS.1996.565232}, Keywords = {Nematic liquid crystals;Fullerenes;Semiconducting films;Semiconductor doping;Polymeric glass;Holographic interferometry;Nonlinear optics;Optical properties;Birefringence;Photolithography;}, Abstract = {The nonlinear optical properties of nematic liquid crystal films doped with dyes of fullerene C<sub>60</sub> are studied. Nematic liquid crystals were doped with azo-dyes, and tested for their optical storage capabilities. An electro-optical holographic storage grating effect is observed in C<sub>60</sub>-doped nematic liquid crystal films. The effect is attributed to molecular axis reorientation caused by the combination of an applied DC field and an optically induced DC space charge. The observed nonlinear sensitivity of the films is larger than that of other materials studied.}, Key = {97013496365} } @article{5385274, Author = {Guenther, B.D. and Narayanan, R.M.}, Title = {Vegetation obscuration effects on mid-infrared laser reflectance of soil}, Journal = {IGARSS '96. 1996 International Geoscience and Remote Sensing Symposium. Remote Sensing for a Sustainable Future (Cat. No.96CH35875)}, Volume = {vol.1}, Pages = {445 - 7}, Address = {Lincoln, NE, USA}, Year = {1996}, url = {http://dx.doi.org/10.1109/IGARSS.1996.516368}, Keywords = {geochemistry;geophysical techniques;infrared imaging;optical radar;remote sensing by laser beam;soil;}, Abstract = {Mid-infrared laser reflectances of soils containing specific minerals show diagnostic features in the 9-11 μm wavelength range, resulting in their suitability for remote sensing of terrestrial lithology. However, the presence of actively growing vegetation can obscure these diagnostic features, in some cases almost completely, so as to make mineral identification virtually impossible. An experimental study was carried out to determine the effects of growing grass on the mid-infrared laser reflectance of bare soil in order to determine the conditions under which the underlying soil reflectance loses its diagnostic features, reflectance ratios (indicative of diagnostic features) were investigated as a function of grass-blade height for different grass densities. It was found that, under specific soil conditions, there appeared a grass-blade height value at which the diagnostic ratios level off to a value of 1.0, thereby masking the underlying soil features. These results are expected to be useful for identifying optimal conditions under which soil mineralogy can be identified under overlying vegetation}, Key = {5385274} } @article{97013501422, Author = {Khoo, I.C. and Wood, M. and Guenther, B.D.}, Title = {Nonlinear liquid crystal optical fiber arrays for all-optical switching/limiting}, Journal = {Conference Proceedings - Lasers and Electro-Optics Society Annual Meeting-LEOS}, Volume = {2}, Pages = {211 - 212}, Address = {Boston, MA, USA}, Year = {1996}, url = {http://dx.doi.org/10.1109/LEOS.1996.571627}, Keywords = {Nonlinear optics;Liquid crystals;Laser pulses;Imaging systems;Optical waveguides;Optical sensors;Light absorption;Doping (additives);Fullerenes;Optical instrument lenses;Optical switches;Optical communication;}, Abstract = {An experiment was carried out to investigate the performance of an optical limiting/protection device which features a liquid crystal fiber array. The fiber core materials, which was made up of isotropic liquid crystal mixture ILC, was doped with a variety of dopant molecules, including an absorbing liquid crystal LC-X and fullerene, to improve its performance. For picosecond laser pulses, the output versus input energy curves for these liquid crystal core materials all exhibit limiting action at rather low threshold, with the clamped output also very low. With optimized dopant concentration and type, other liquid crystals with high two-photon absorption coefficient, much lower threshold and clamped transmission were obtained.}, Key = {97013501422} } @article{5744526, Author = {Khoo, I.C. and Wood, M.V. and Guenther, B.D.}, Title = {Photorefractivity and holographic storage effect in fullerene C60-doped nematic liquid crystals}, Journal = {Liquid Crystals for Advanced Technologies. Symposium}, Pages = {203 - 12}, Address = {San Francisco, CA, USA}, Year = {1996}, Keywords = {electro-optical effects;fullerenes;holographic storage;light diffraction;nematic liquid crystals;nonlinear optics;photoconductivity;photorefractive effect;}, Abstract = {The results of a recent study of a nonlinear electro-optical effect in fullerene C<sub>60</sub>-doped nematic liquid crystal film are presented. In particular, photo-induced conduction, self diffraction effect, and permanent holographic formation in the films are explained}, Key = {5744526} } @article{5434860, Author = {Khoo, IC and Wood, MV and Lee, M and Guenther, BD}, Title = {Nonlinear liquid-crystal fiber structures for passive optical limiting of short laser pulses}, Journal = {Opt. Lett. (USA)}, Volume = {21}, Number = {20}, Pages = {1625-1627}, Year = {1996}, Keywords = {fluctuations;high-speed optical techniques;laser beam effects;laser beams;light absorption;light scattering;limiters;liquid crystal devices;nonlinear optics;optical fibres;refractive index;thermo-optical effects;}, Abstract = {Optical limiting of nanosecond and picosecond laser pulses through millimeter-length isotropic liquid-crystal-cored fiber structures is reported. Low limiting threshold and clamped transmitted outputs are observed. The underlying nonlinear mechanisms are nonlinear photoabsorptions and scattering and lossy waveguiding caused by laser-induced thermal-density index fluctuations}, Key = {5434860} } @article{5260944, Author = {Yin, S and Guenther, BD and Yu, FTS}, Title = {A tunable narrow-band filter using a photorefractive fiber}, Journal = {Opt. Mem. Neural Netw. (USA)}, Volume = {5}, Number = {1}, Pages = {35-41}, Year = {1996}, Keywords = {diffraction gratings;electro-optical effects;optical design techniques;optical fibre filters;photorefractive materials;refractive index;tuning;}, Abstract = {In this paper, the design of a high signal-to-noise ratio (SNR) tunable filter using a single crystal photorefractive (PR) fiber is given. Because of the long physical structure, Bragg gratings of a large number of periods can be synthesized within the fiber. The wavelength selectivity of 105 order can be realized, which is suitable to develop a narrow-band filter in the order of 0.01 nm. By using a multiple grating structure in the fiber, a high SNR of about 40 db is achievable in practice. Since the PR fiber has a high electro-optic constant, the refractive index of the fiber can be varied by an applied electric field, for which the tuning speed can be in the ns range}, Key = {5260944} } @article{97083766919, Author = {Goyette, TM and Guo, W and De Lucia and FC and Brown, ER and McIntosh, KA and Juvan, K and Swartz, JC and Everitt, HO and Guenther, BD}, Title = {High resolution sub-millimeter spectroscopy using mode-locked laser driven electro-optic antennas}, Journal = {Springer Series in Chemical Physics}, Number = {62}, Pages = {56}, Year = {1996}, Key = {97083766919} } @article{5718272, Author = {Guenther, BD and Wood, MV and Khoo, IC}, Title = {Photorefractivity, phase conjugation and thermal wave mixing effects in the visible and near IR spectral region for dye and fullerene C60-doped nematic liquid crystals}, Journal = {Proc. SPIE - Int. Soc. Opt. Eng. (USA)}, Volume = {2854}, Pages = {151-159}, Address = {Denver, CO, USA}, Year = {1996}, Keywords = {electro-optical effects;fullerenes;liquid films;multiwave mixing;nematic liquid crystals;nonlinear optics;optical phase conjugation;organic compounds;photorefractive effect;thermo-optical effects;}, Abstract = {The results of a recent study of a nonlinear electro-optical effect in dye and fullerene C60-doped nematic liquid crystal films are presented. In particular, photo-induced conduction, self diffraction effects, and optical phase conjugation in the films from near-UV to near-IR wavelengths are explained}, Key = {5718272} } @article{96012997722, Author = {Goyette, TM and Guo, W and DeLucia, FC and Swartz, JC and Everitt, HO and Guenther, BD and Brown, ER}, Title = {Femtosecond demodulation source for high-resolution submillimeter spectroscopy}, Journal = {Applied Physics Letters}, Volume = {67}, Number = {25}, Pages = {3810-3812}, Year = {1995}, Month = {December}, ISSN = {0003-6951}, url = {http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:A1995TK75900047&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=47d3190e77e5a3a53558812f597b0b92}, Doi = {10.1063/1.115391}, Key = {96012997722} } @article{5146287, Author = {SWARTZ, JC and GUENTHER, BD and DELUCIA, FC and GUO, W and JONES, CR and KOSAI, H and DUTTA, JM}, Title = {NONDESTRUCTIVE DIAGNOSTICS FOR RELATIVISTIC PICOSECOND BUNCHED ELECTRON-BEAMS}, Journal = {Physical Review E - Statistical Physics, Plasmas, Fluids, and Related Interdisciplinary Topics}, Volume = {52}, Number = {5}, Pages = {5416-5424}, Year = {1995}, Month = {November}, ISSN = {1063-651X}, url = {http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:A1995TG33700038&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=47d3190e77e5a3a53558812f597b0b92}, Keywords = {electron beams;particle beam diagnostics;rectangular waveguides;relativistic electron beam tubes;}, Abstract = {The duration and form of relativistic picosecond electron bunches in the Duke University Mark III free-electron laser have been nondestructively measured by monitoring the submillimeter radiation produced by the bunches as they pass by or through a rectangular waveguide. Unlike other methods, our technique produces negligible electron bunch perturbation and allows real-time beam diagnostics to be performed simultaneously with free-electron laser (FEL) operation. We have measured 2.1-ps full width at half maximum duration electron bunches, studied the effect of electron gun and FEL modifications on bunch duration, and observed electron bunch variations during bunch trains}, Doi = {10.1103/PhysRevE.52.5416}, Key = {5146287} } @article{95092876404, Author = {JONES, CR and KOSAI, H and DUTTA, JM and PETERS, MJ and GUO, W and DELUCIA, FC and BENSON, SV and MADEY, JMJ and SWARTZ, JC and GUENTHER, BD}, Title = {GENERATION OF PICOSECOND PULSES AT MILLIMETER WAVELENGTHS}, Journal = {Applied Physics Letters}, Volume = {67}, Number = {10}, Pages = {1483-1485}, Year = {1995}, Month = {September}, ISSN = {0003-6951}, url = {http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:A1995RR44000048&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=47d3190e77e5a3a53558812f597b0b92}, Doi = {10.1063/1.114502}, Key = {95092876404} } @article{5207879, Author = {Yin, S and Guenther, BD and Yu, FTS}, Title = {Narrow-band filter using multiple photorefractive gratings}, Journal = {Proc. SPIE - Int. Soc. Opt. Eng. (USA)}, Volume = {2529}, Pages = {196-203}, Address = {San Diego, CA, USA}, Year = {1995}, Keywords = {electro-optical effects;holographic gratings;optical fibre filters;photorefractive effect;refractive index;tuning;}, Abstract = {In this paper, we propose a novel high SNR tunable filter using a photorefractive single crystal fiber with multiple holographic gratings. Since the single crystal fiber which is grown by the laser heated pedestal growth (LHPG) technique can be more than 100 mm long, volume gratings with extremely large number of period can be obtained in the fiber. Thus, the wavelength selectivity of the grating can be very high on the order of 105 so that one can achieve very narrow band filter (<0.01 nm). To increase the signal-to-noise ratio (SNR) of the filter, a method of using multiple holographic gratings is proposed. The SNR can be improved by more than 100 times as compared with a conventional volume grating filter. Finally, the electro-optic effect can be used to change the refractive index of the crystal fiber, which in turn changes the wavelength response of the stored volume grating. Since the response time of the electro-optic effect is on the order of 1 ns, one can very rapidly tune the central-wavelength of the filter}, Key = {5207879} } @article{93071637884, Author = {Phillips, PJ and von Ramm, OT and Swartz, JC and Guenther, BD}, Title = {Optical transducer for reception of ultrasonic waves.}, Journal = {The Journal of the Acoustical Society of America}, Volume = {93}, Number = {2}, Pages = {1182-1191}, Year = {1993}, Month = {February}, ISSN = {0001-4966}, url = {http://www.ncbi.nlm.nih.gov/pubmed/8445122}, Abstract = {A new optical transducer for the detection of acoustic pressure in the diagnostic ultrasound frequency range is described. This transducer is based on the modulation of an evanescent light field by the incident acoustic energy. Theoretical design considerations are presented for the purpose of developing the most sensitive transducer. Based on these considerations an experimental transducer was constructed. Although less sensitive than predicted this device was capable of transducing ultrasonic pulses with a 1.0-MHz center frequency at diagnostic ultrasound amplitude levels. The techniques developed here are applicable for two-dimensional transduction and may prove a viable alternative to piezoelectric array transducers.}, Key = {93071637884} } @article{93121755607, Author = {Guenther, B.D.}, Title = {Keynote address. Manufacturing the key to binary optics}, Journal = {NASA Conference Publication}, Number = {3227}, Pages = {1 -}, Address = {Huntsville, AL, USA}, Year = {1993}, Key = {93121755607} } @article{92060518040, Author = {GUENTHER, BD and VANDERLUGT, A}, Title = {INTERFERENCE AND FRESNEL DIFFRACTION}, Journal = {IEEE Transactions on Education}, Volume = {35}, Number = {2}, Pages = {126-132}, Year = {1992}, Month = {May}, ISSN = {0018-9359}, url = {http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:A1992HU43600007&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=47d3190e77e5a3a53558812f597b0b92}, Keywords = {Mathematical Transformations - Fourier Transforms;Light - Diffraction;Holography;Microscopic Examination;}, Abstract = {It is shown that a surprising number of traditional topics, such as the Rayleigh resolution criterion, spatial filtering, bandlimited signals, the sampling theorem, phase contrast microscopy, and white light holography, can be explained using simple interference theory. These basic results are then easily extended to the N-source case to introduce diffraction theory, and facilitate the teaching of the elements of modern optics to junior and senior-level students.}, Doi = {10.1109/13.135577}, Key = {92060518040} } @article{3625762, Author = {LAM, JF and GUENTHER, BD and SKATRUD, DD}, Title = {THEORY OF MILLIMETER WAVE NONLINEARITIES IN SEMICONDUCTOR SUPERLATTICES}, Journal = {Applied Physics Letters}, Volume = {56}, Number = {8}, Pages = {773-775}, Year = {1990}, Month = {February}, ISSN = {0003-6951}, url = {http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:A1990CP30100025&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=47d3190e77e5a3a53558812f597b0b92}, Keywords = {harmonic generation;self-induced transparency;semiconductor superlattices;}, Abstract = {A study of the impact of semiconductor superlattices on millimeter wave nonlinearities is reported. χ<sup>(3)</sup> as large as 10<sup>-2</sup> esu can be achieved by using 250 GHz radiation. Self-induced transparency is also predicted, and its competition with the third-harmonic generation process is quantified}, Doi = {10.1063/1.102709}, Key = {3625762} } @booklet{Caulfield90, Author = {Caulfield, HJ and Goodman, JW and Guenther, RD and Hendrickson, BM and Neff, JA and Rhodes, WT and Turpin, TM and Yang, A}, Title = {Goals for optical signal-processing and optical computing in the 1990s}, Journal = {Laser Focus World}, Volume = {26}, Number = {1}, Pages = {143-146}, Year = {1990}, Month = {January}, Key = {Caulfield90} } @article{3614029, Author = {Swartz, J.C. and De Lucia and F.C. and Guenther, B.D.}, Title = {Application of frequency-domain techniques for tuning pulsed lasers}, Journal = {OSA Proceedings on Picosecond Electronics and Optoelectronics Volume 4. Proceedings of the OSA Topical Meeting}, Pages = {57 - 60}, Address = {Salt Lake City, UT, USA}, Year = {1989}, Keywords = {dye lasers;laser mode locking;laser tuning;}, Abstract = {Demonstrates an alternative technique to the use of an autocorrelator for accurately tuning pulsed lasers. This technique is based upon the use of frequency domain information in place of the time domain information to obtain the optimum modelocked condition}, Key = {3614029} } @article{3604172, Author = {Stone, T and George, N and Guenther, BD}, Title = {Index variation and scattering in a holographic medium}, Journal = {Proc. SPIE - Int. Soc. Opt. Eng. (USA)}, Volume = {1136}, Pages = {35-44}, Address = {Paris, France}, Year = {1989}, Keywords = {holographic gratings;holographic optical elements;light scattering;refractive index measurement;spectrophotometry;}, Abstract = {In the fabrication of holographic optical elements, it is important to have careful characterization of the recording medium. Hence, the authors have made measurements of the increment in the index of refraction vs. exposure for DMP-128 manufactured by Polaroid corporation. The results of measurements are presented for a series of holographic diffraction gratings. A novel spectrometer technique that provides a simultaneous measure of both thickness and refractive index is described. Data illustrating its use are presented for the holographic photopolymer. The feasibility of filling voids in the processed photopolymer for device applications was demonstrated by construction of a distributed feedback dye laser in a DMP-128 grating. At high spatial frequencies, diffraction efficiency is used to estimate refractive index variations. As an initial finding, the authors report a rather large modulation in the index of refraction of 0.2 at 1000 cycles/mm}, Key = {3604172} } @article{3229262, Author = {Anderson, GW and Guenther, BD and Hynecek, JA and Keyes, RJ and VanderLugt, A}, Title = {Role of photodetectors in optical signal processing}, Journal = {Appl. Opt. (USA)}, Volume = {27}, Number = {14}, Pages = {2871-2886}, Year = {1988}, Keywords = {optical information processing;photodetectors;}, Abstract = {Optical signal processing applications place demands on photodetector arrays beyond those encountered in image sensing applications. The authors review the basic requirements and show that increased dynamic range and nonlinear decision operations that lead to reduced output data rates are the key improvements needed for both 1- and 2-D arrays. Arrays of high-speed photodetector elements with integrated postdetection circuitry are also needed. Although they suggest some possible methods for achieving these goals, their main objective is to simulate the photodetector community to design and fabricate more useful devices}, Key = {3229262} } @article{3268777, Author = {Hay, WC and Guenther, BD}, Title = {Characterization of Polaroid's DMP-128 holographic recording photopolymer}, Journal = {Proc. SPIE - Int. Soc. Opt. Eng. (USA)}, Volume = {883}, Pages = {102-105}, Address = {Los Angeles, CA, USA}, Year = {1988}, Keywords = {holography;photographic emulsions;polymers;}, Abstract = {The fundamental holographic properties of Polaroid's DMP-128 have been measured. Diffraction efficiencies over 90% have been obtained with an index modulation of 0.033. It was found that the diffraction efficiency could be reduced from 90% to less than 10% by the use of an index matching fluid. When the index matching fluid was allowed to evaporate, the diffraction efficiency returned to its original value. This observation suggests that the index modulation produced in the photopolymer is due to tiny cracks or voids formed in the polymer}, Key = {3268777} } @article{3392225, Author = {Guenther, BD}, Title = {Gradients and their applications}, Journal = {Proc. SPIE - Int. Soc. Opt. Eng. (USA)}, Volume = {935}, Pages = {95-104}, Address = {Orlando, FL, USA}, Year = {1988}, Keywords = {gradient index optics;military equipment;}, Abstract = {The use of gradient properties in a wide range of physical processes are discussed with emphasis on optical applications of interest to the military}, Key = {3392225} } @article{2587580, Author = {DELUCIA, FC and GUENTHER, BD and ANDERSON, T}, Title = {MICROWAVE GENERATION FROM PICOSECOND DEMODULATION SOURCES}, Journal = {Applied Physics Letters}, Volume = {47}, Number = {8}, Pages = {894-896}, Year = {1985}, ISSN = {0003-6951}, url = {http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:A1985ARS4600050&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=47d3190e77e5a3a53558812f597b0b92}, Keywords = {demodulation;microwave generation;microwave tubes;}, Abstract = {A mode-locked picosecond laser has been used to prebunch electron beams at a photocathode. These electrons are subsequently accelerated through coupling structures and microwaves radiated. The relation between the microwave output and the properties of the picosecond pulse train and the electron beam output coupling process are reported and related to theory. Among the important attributes of these devices are their ability to generate almost arbitrary microwave waveforms, to operate in the 100-200 kV region with very simple power supplies and excellent spectral purity, and to generate substantially more microwave power than contained in the optical drive}, Doi = {10.1063/1.95968}, Key = {2587580} } @article{1951750, Author = {Guenther, BD and Buser, RG}, Title = {Tunable lasers-an overview}, Journal = {IEEE J. Quantum Electron. (USA)}, Volume = {QE-18}, Number = {8}, Pages = {1179-1184}, Year = {1982}, Keywords = {laser tuning;reviews;}, Key = {1951750} } @article{83030037371, Author = {Mink, JW and Guenther, BD}, Title = {PLEA FOR SYNERGISM.}, Journal = {Proceedings of SPIE - The International Society for Optical Engineering}, Volume = {317}, Pages = {10-14}, Address = {Huntsville, AL, USA}, Year = {1982}, Keywords = {WAVEGUIDES;}, Key = {83030037371} } @article{1999923, Author = {Mink, JW and Guenther, BD}, Title = {Plea for synergism [MM/subMM wave IC]}, Journal = {Proc. SPIE - Int. Soc. Opt. Eng. (USA)}, Volume = {317}, Pages = {10-14}, Address = {Huntsville, AL, USA}, Year = {1981}, Keywords = {dielectric waveguides;economics;integrated circuit technology;integrated optics;microwave integrated circuits;military equipment;}, Abstract = {Because of the proposed number of units expected to utilize millimeter/submillimeter waves in the military (on the scale of 50000 items/system) it is vital to develop the technology base such that it will economically support the manufacture of millimeter wave systems. The technology which holds the greatest potential to meet the military requirements above 100 GHz will probably be based upon dielectric waveguides. That technology must be developed so that low cost, reproducible millimeter/submillimeter wave integrated circuits will be available}, Key = {1999923} } @article{80060007211, Author = {Guenther, BD and Christensen, CR and Upatnieks, J}, Title = {COHERENT OPTICAL PROCESSING: ANOTHER APPROACH.}, Journal = {IEEE Journal of Quantum Electronics}, Volume = {QE-15}, Number = {12}, Pages = {1348-1362}, Year = {1979}, url = {http://dx.doi.org/10.1109/JQE.1979.1069953}, Keywords = {OPTICAL DATA PROCESSING;}, Abstract = {Demonstration of real-time coherent optical correlation for both vehicle tracking and identification has been demonstrated. A reference filter has been constructed that can recognize a vehicle from all orientations. A design of a coherent optical processor is presented using laser diode light sources and having a package size of 50 cm**3.}, Doi = {10.1109/JQE.1979.1069953}, Key = {80060007211} } @article{80060002737, Author = {Smith, JL and Guenther, BD and Christensen, CR}, Title = {REAL-TIME OPTICAL PROCESSING USING THE LIQUID CRYSTAL LIGHT VALVE.}, Journal = {Journal of Applied Photographic Engineering}, Volume = {5}, Number = {4}, Pages = {236-243}, Year = {1979}, Keywords = {CRYSTALS, LIQUID - Applications;}, Abstract = {Implementation of the liquid crystal light valve in several coherent optical processing schemes is demonstrated. Experiments were designed to extend conventional techniques to real-time and explore new applications concepts. These are (1) real-time holography for adaptive optics, (2) Doppler imaging using the light valve for coherent detection with a frequency coded reference beam, (3) object recognition and tracking via cross-correlation with Vander Lugt filters, (4) time-average speckle imagery for discrimination of slowly moving objects, and finally (5) range-slice imagery and range-Doppler simulation.}, Key = {80060002737} } @article{1238717, Author = {Guenther, B.D. and Christensen, C.R. and Anil Jain}, Title = {Digital processing of speckle images}, Journal = {Proceedings of the 1978 Conference on Pattern Recognition and Image Processing}, Pages = {85 - 90}, Address = {Chicago, IL, USA}, Year = {1978}, Keywords = {digital filters;digital simulation;picture processing;probability;speckle;}, Abstract = {A digital model of an image with speckel noise is constructed and verified by comparison to optically generated images with speckle noise. The model is then used to obtain detection probabilities and to evaluate several digital filtering techniques}, Key = {1238717} } @article{1208625, Author = {Gamble, W.L. and Guenther, B.D. and Hartman, R.L. and Osmundsen, J.F. and Kruse, P.W.}, Title = {MIRADCOM far infrared imaging radar program}, Journal = {Proceedings of the Society of Photo-Optical Instrumentation Engineers, vol.105. Far Infared/Submillimeter Wave}, Pages = {102 - 11}, Address = {Reston, VA, USA}, Year = {1977}, Keywords = {infrared imaging;radar;radar measurement;radar systems;}, Abstract = {The US Army Missile Research and Development Command has set up an instrumented propagation range at Redstone Arsenal, Alabama, for the purpose of systematically identifying and exploring the effects of the atmosphere and materials reflectance (natural and cultural) on high angular resolution radar systems. The emphasis will be on propagation and reflectance measurements in the water vapor absorption windows around 730, 870 and 1200 micrometers. The techniques, apparatus, and goals are described}, Key = {1208625} } @article{1136373, Author = {Guenther, BD and George, N and Christensen, CR and Bennett, JS}, Title = {Speckle noise and object contrast}, Journal = {Photographic Science and Engineering}, Volume = {21}, Number = {4}, Pages = {192-197}, Year = {1977}, Keywords = {optical images;optical information processing;optical systems;photography;speckle;}, Abstract = {A technique is demonstrated for evaluation of detection thresholds as a function of object size and contrast in coherent imaging systems. Several experiments are used to illustrate the application of this technique: (a) A study of three different methods of speckle smoothing; (b) a demonstration that speckle decorrelates with input polarization; and (c) a demonstration that fully-developed speckle leads to an image degradation independent of light level over a very wide range of light levels. Photographic data are provided to illustrate the effectiveness of this technique}, Key = {1136373} } @article{1053062, Author = {Gamble, W.L. and Guenther, B.D.}, Title = {Submillimeter laser wave propagation}, Journal = {2nd International Conference and Winter School on Submillimeter Waves and their Applications}, Pages = {231 - 2}, Address = {San Juan, Puerto Rico}, Year = {1976}, Keywords = {atmospheric light propagation;atmospheric measuring apparatus;laser beams;optical radar;optical resolving power;}, Abstract = {Describes primarily the apparatus, techniques, goals and some preliminary results of the US Army Missile Command submillimeter wave program. The basic question is that of the range and effective angular resolution of scanned submillimeter radar systems in particular during meteorological conditions of severely limited visibility. The most critical propagation issues are water vapour absorption, extinction due to aerosols, and beam degradation effects, if any, due to atmospheric turbulence}, Key = {1053062} } @article{76030005260, Author = {Aleksoff, C. C. and Guenther, B. D.}, Title = {CROSS-CORRELATION DISCRIMINATION FOR OPTICAL CAVITY MODES.}, Journal = {Applied Optics}, Volume = {15}, Number = {1}, Pages = {206 - 217}, Year = {1976}, Keywords = {RESONATORS, CAVITY;}, Abstract = {Matched spatial filters were constructed for various modes of a spherical Fabry-Perot interferometer (FPSI). The cross correlation between many of these modes was obtained experimentally as well as theoretically. The orthogonality between various modes was demonstrated and used in order to discriminate against all orthogonal modes. A discrimination function that predicts the performance of the matched-filtering process is defined and analytically evaluated for rectangular and cylindrical Gaussian modes. It is shown that arbitrary discrimination strength can be obtained at the sacrifice of output signal strength. It was experimentally demonstrated that a scanning FPSI used in conjunction with only one zero-order-mode filter could be used over nearly its entire domain of stable cavity spacings and still maintain a full (c/2L) free spectral range.}, Key = {76030005260} } @article{921436, Author = {Schlie, LA and Guenther, BD and Rathge, RD}, Title = {Positive gain measurements on the 3350-Å continuum band of Hg2}, Journal = {Appl. Phys. Lett. (USA)}, Volume = {28}, Number = {7}, Pages = {393-396}, Year = {1976}, url = {http://dx.doi.org/10.1063/1.88772}, Keywords = {gas lasers;mercury (metal);}, Abstract = {Positive gain measurements are reported on the flanks of the 3350 Å continuum band in mercury vapour at 3.72 atm. pressure, pumped by a 600 J, 1.5 MeV, 20 nsec. pulsed electron beam. The stimulated emission cross section at three probe wavelengths is approximately 10-18 cm2, exceeding photoabsorption by any process in Hg/Hg2. The laser gain signals are reported to be further enhanced in vapours heated above the saturation temperature, indicating that the upper level is populated by a temperature dependent internal energy reservoir}, Doi = {10.1063/1.88772}, Key = {921436} } @article{1034989, Author = {George, N and Christensen, CR and Bennett, JS and Guenther, BD}, Title = {Speckle noise in displays}, Journal = {J. Opt. Soc. Am. (USA)}, Volume = {66}, Number = {11}, Pages = {1282-1290}, Year = {1976}, Keywords = {display instrumentation;noise;optical radar;radar displays;speckle;}, Abstract = {An expression is derived for the minimum detectable contrast level for an object in presence of speckle noise. The threshold limits of the discernible contrast with variation of the statistical parameters of the illumination are studied. Minimum detectable contrast is measured for two classes of speckle noise i) the coherent superposition of a plane wave and a diffuse (fully developed speckle) beam, the threshold being established as a function of beam ratio, and ii) the intensity superposition of N-independent fully developed speckle patterns. The effects of smoothing by area and by multiple looks are considered. Experimental results are in good agreement with theory}, Key = {1034989} } @article{908389, Author = {Aleksoff, CC and Guenther, BD}, Title = {Cross-correlation discrimination for optical cavity modes}, Journal = {Applied Optics}, Volume = {15}, Number = {1}, Pages = {206-217}, Year = {1976}, Keywords = {correlators;holography;laser cavity resonators;light interferometers;optical filters;optical information processing;}, Abstract = {A hologram can act as a matched spatial filter, i.e. as a correlator of two wavefronts. Correlation between the wavefront stored in the hologram and the incident wavefront is displayed as a two dimensional spatial distribution in the correlation plane. If a matched filter is produced for one of the modes of an open optical resonator, it can discriminate against all the other orthogonal modes. Theory and experimental results for matched spatial filters for the modes of a spherical Fabry-Perot interferometer (SFP1) are described. Effects of matched filtering of scanning SFP1 are shown. Experimental cross-correlation and autocorrelation functions for circularly symmetric and for rectangular modes are also shown. Fourier transform, convolution, and correlation characteristics of modes are tabulated}, Key = {908389} } @article{830853, Author = {Schlie, LA and Guenther, BD and Drummond, DL}, Title = {Origin of the 4400 Å and 5300 Å bands of Hg2}, Journal = {Chem. Phys. Lett. (Netherlands)}, Volume = {34}, Number = {2}, Pages = {258-260}, Year = {1975}, url = {http://dx.doi.org/10.1016/0009-2614(75)85267-5}, Keywords = {fluorescence;mercury (metal);molecular excited states;molecular vibration;}, Abstract = {Previously reported spectral data from e-beam excited Hg vapor contains bands at 4400 Å and 5300 Å whereas other excitation methods produce a band centered at 5100 Å. The probable origin of the anomalous e-beam produced spectrum is shown to be the vibrational non-equilibrium of the Hg2 (A30u-) state. Time resolved spectra are presented}, Doi = {10.1016/0009-2614(75)85267-5}, Key = {830853} } @article{416298, Author = {Bendall, CR and Guenther, BD}, Title = {Technique for obtaining a photomicrograph of a cross section of photographic emulsion}, Journal = {Appl. Opt. (USA)}, Volume = {11}, Number = {7}, Pages = {1653}, Year = {1972}, Keywords = {photographic materials;}, Key = {416298} } @article{475254, Author = {Bendall, CR and Guenther, BD and Hartman, RL}, Title = {Thick amplitude holograms: effect of nonlinear recording}, Journal = {Appl. Opt. (USA)}, Volume = {11}, Number = {12}, Pages = {2992-2993}, Year = {1972}, Keywords = {holography;}, Abstract = {A modification is made of the coupled wave theory to describe the observed behaviour of a nonlinearly recorded hologram}, Key = {475254} } @article{310588, Author = {Richards, PM and Christensen, CR and Guenther, BD and Daniel, AC}, Title = {Nuclear-magnetic-resonance echo enhancement in an antiferromagnet}, Journal = {Phys. Rev. B, Solid State (USA)}, Volume = {4}, Number = {7}, Pages = {2216-2224}, Year = {1971}, url = {http://dx.doi.org/10.1103/PhysRevB.4.2216}, Keywords = {antiferromagnetic properties of substances;manganese compounds;nuclear magnetic resonance;}, Abstract = {The observation of an anomalous enhancement of a two-pulse nuclear spin echo in antiferromagnetic MnO by a prepulse of variable width, amplitude, and delay time is described. A theory explaining this observation by adding frequency pulling to the Block equations is discussed. In this model the frequency pulling parameter is assumed to be inhomogeneous throughout the sample, consistent with current ideas of NMR line broadening in materials with strong pulling. Long free-induction decays observed following wide pulses are also explained}, Doi = {10.1103/PhysRevB.4.2216}, Key = {310588} } @article{262345, Author = {Guenther, BD and Christensen, CR and Jensen, RA and Daniel, AC}, Title = {Capacitively and inductively foreshortened cavities for magnetic resonance spectroscopy}, Journal = {Rev. Sci. Instrum. (USA)}, Volume = {42}, Number = {4}, Pages = {431-434}, Year = {1971}, Keywords = {cavity resonators;magnetic resonance spectrometers;nuclear magnetic resonance;resonators;}, Abstract = {Two types of cylindrical reentrant cavities are described for magnetic resonance and ultrasonic applications in the 0.1-1.0 GHz frequency region. The physical size of these cavities is reduced by introducing large capacitive and inductive elements into the cavity. Tuning, rf coupling, and temperature control techniques are described for operation at low temperatures}, Key = {262345} } @article{285315, Author = {Daniel, A.C. and Guenther, B.D. and Christensen, C.R.}, Title = {Echo amplification in magnetic materials with application to pulse compression radar}, Volume = {unnumbered}, Pages = {15 -}, Year = {1970}, Keywords = {ferrite applications;ferrites;garnets;nuclear magnetic resonance;radar receivers;}, Abstract = {Echo phenomena in several materials have been reviewed for the purpose of considering the recently proposed amplified spin echo as a chirp radar receiver. The technique is believed to exhibit considerable merit in that a number of desirable characteristics have been combined in a unique manner. If properly realized, a portion of the processing of the radar signal could be accomplished at the antenna feed element. However, the available materials still limit the practical usefulness of this device as compared to more conventional techniques}, Key = {285315} } @article{224233, Author = {Guenther, BD and Christensen, CR and Daniel, AC and Richards, PM}, Title = {NMR and AFMR modes in antiferromagnetic MnO}, Journal = {Phys. Lett. A (Netherlands)}, Volume = {33a}, Number = {6}, Pages = {355-357}, Year = {1970}, Keywords = {antiferromagnetic resonance;manganese compounds;nuclear magnetic resonance;}, Abstract = {NMR modes in antiferromagnetic MnO are interpreted in terms of a two sublattice model. Observation of AFMR mode at 27.6 GHz correlates with this interpretation}, Key = {224233} } @article{149180, Author = {Christensen, CR and Guenther, BD and Daniel, AC}, Title = {NMR observation of domain structure in antiferromagnetic MnO}, Journal = {J. Appl. Phys. (USA)}, Volume = {41}, Number = {3}, Pages = {1113}, Address = {Philadelphia, PA, USA}, Year = {1970}, Keywords = {antiferromagnetic properties of substances;magnetic domains;manganese compounds;nuclear magnetic resonance;nuclei with 39⩽A⩽58;nuclei with 59⩽A⩽89;}, Abstract = {Abstract only given, substantially as follows. The frequency pulled 55Mn nuclear resonance in MnO at 4.2°K was observed as a function of the angle of rotation of the applied field H0 about a [111] direction. The resonance spectrum was found to consist of one branch, independent of the position of H0, and three other branches which coincide in frequency with the angle independent branch at 60° periods and move to lower frequencies at other positions of H0. These branches correspond to resonance in antiferromagnetic T-domains ordered along the four equivalent [111] directions. The components of H0 perpendicular to each of the [111] directions were calculated as a function of magnet angle}, Key = {149180} } @article{107233, Author = {Guenther, BD and Christensen, CR and Daniel, AC}, Title = {55Mn nuclear magnetic resonance in antiferromagnetic MnO}, Journal = {Phys. Lett. A (Netherlands)}, Volume = {30a}, Number = {7}, Pages = {391-392}, Year = {1969}, Keywords = {manganese compounds;nuclear magnetic resonance;nuclei with 39⩽A⩽58;nuclei with 59⩽A⩽89;}, Abstract = {One of the two 55Mn nuclear magnetic resonances in MnO at 4.2°K is found to be only slightly dependent upon the magnet field, whereas the second is relatively strongly pulled with decreasing field and unobservable below 12 kOe}, Key = {107233} }