Anomalous transport of light in photonic crystal

Abstract

Photonic crystal (PC) offers a powerful means to mold the flow of light and manipulate lightmatter interaction at subwavelength scale. In this paper, we review some recent theoretical and experimental work in our group on design and fabrication of microwave and infrared PC structures with the capability to achieve various anomalous transport behaviors of light. We discuss several microwave 2D PC and quasi-crystal structures that exhibit nearly isotropic equi-frequency surface (EFS) contours with effective refractive index equal to -1. In these structures, we can observe negative refraction induced focusing of microwave against a flat slab lens in non-near field regions. In comparison, if PC structures have anisotropic EFS contours in the lowest photonic band, only near-field focusing is expected. We move forward to high frequency infrared band and exploreremarkable dispersion properties of silicon 2D PC slab to achieve broad-band negative refraction and self-collimation transport of infrared light beam. We also explore the possibility to realize negative refraction and flat-lens focusing of light in 3D PC made from inverse opal. These studies show that PCs can offer a powerful route to manipulate various anomalous transport of light via photonic band gap and band structure engineering, which can be harnessed to build a wide variety of integrated optical devices for large-scale optical integration.