Enhanced backscattering for infrared detection using photonic crystal based flat lens

Abstract

An n=-1 flat lens based on photonic crystal semiconductor technology is evaluated for infrared detection purposes. The idea consists in exploiting the backscattered waves of an incident plane wave impinging on a target placed in the focal region of a flat lens. It is shown that subwavelength detection of micronic dielectric targets can be obtained at 1.55 μm using the double focus of reflected waves induced by negative refraction. Complex relations among the intrinsic nature, the shape and size of the target, and detection efficiency are interpreted in terms of target eigenmode excitation. Reflectivity is modulated by the intrinsic mode nature, transverse, circular, or longitudinal, with an enhancement of the detection sensitivity in the case of whispering-gallery modes. It is believed that such a study paves the way to the definition of original noninvasive infrared sensors.

Design and analysis of superlens based on complex two-dimensional square lattice photonic crystal

“…The other structure is a periodic array of lossless dielectric materials called photonic crystals (PCs). Although the PC constituent elements are dielectrics with positive electric and magnetic responses to electromagnetic (EM) waves, PCs can behave as superlensing devices with an effective negative refractive index at infrared and visible frequency regimes [6] , which are the important frequency regions in biomedical and nanoscale optical imaging, high-density optoelectronic devices, and optical communication technologies [7] . Negative refractions in PCs and LHMs are slightly different.…”