Third-order nonlinear influence on the specular reflectivity of two-dimensional waveguide-based photonic crystals

Specular reflectivity spectra of plane waves incident upon two-dimensional waveguide-based photonic crystals are rigorously calculated by use of the linear and the third-order nonlinear susceptibilities of the semiconductor core layer. The Fano-like features associated with coupling to leaky photonic eigenstates that are attached to the porous slab are shifted and distorted at high intensities. Although some of this nonlinear behavior is qualitatively similar to that observed in simple Fabry-Perot cavities, there are striking differences. The main difference is that one can engineer the Q values and the in-plane dispersion of the microcavity modes associated with the leaky eigenstates of the photonic crystal over a wide range by varying the properties of the etched texture. Examples are given that demonstrate bistable behavior and intensity-dependent reflectivities that can vary from zero to unity. Both degenerate (single-beam) and nondegenerate (pump- and signal-beam) cases are considered. (C) 2002 Optical Society of America.