Publications [#269772] of David R. Smith

Papers Published
  1. Urzhumov, Y; Smith, DR, Low-loss directional cloaks without superluminal velocity or magnetic response., Optics Letters, vol. 37 no. 21 (November, 2012), pp. 4471-4473 [23114333] .

    The possibility of making an optically large (many wavelengths in diameter) object appear invisible has been a subject of many recent studies. Exact invisibility scenarios for large (relative to the wavelength) objects involve (meta)materials with superluminal phase velocity [refractive index (RI) less than unity] and/or magnetic response. We introduce a new approximation applicable to certain device geometries in the eikonal limit: piecewise-uniform scaling of the RI. This transformation preserves the ray trajectories but leads to a uniform phase delay. We show how to take advantage of phase delays to achieve a limited (directional and wavelength-dependent) form of invisibility that does not require loss-ridden (meta)materials with superluminal phase velocities.