Photonic Bloch waves and field microstructure in nonlinear gratings: An intuitive approach

Abstract

Coupled wave theory is commonly used in numerical simulations of reflection from nonlinear grating structures. By contrast, the complementary photonic Bloch wave (PBW) approach has rarely been adopted, perhaps the only example being recent work on gap solitons. Bloch wave theory offers an alternative physical intuitive picture that encourages one to think in terms of field microstructure, leading to a range of simple explanations for the behaviour of light in linear gratings. In this paper the dispersion relation and field microstructure of Bloch waves are found, and used to clarify the physical mechanisms that lead to regions of bistability, instability and oscillation for incidence of a monochromatic plane wave on a nonlinear grating half-space