Coupled Wave Theory for Thick Hologram Gratings

TLDR

Coupled‑wave analysis of Bragg diffraction in thick hologram gratings extends dynamical diffraction theory, remaining valid even at high efficiencies where the incident wave is strongly depleted. The authors derive algebraic expressions for diffraction efficiencies, angular and wavelength sensitivities, and numerically evaluate them for transmission and reflection holograms, incorporating refractive‑index and absorption modulations, loss, and slanted fringes.

Abstract

A coupled wave analysis is given of the Bragg diffraction of light by thick hologram gratings, which is analogous to Phariseau's treatment of acoustic gratings and to the “dynamical” theory of X-ray diffraction. The theory remains valid for large diffraction efficiencies where the incident wave is strongly depleted. It is applied to transmission holograms and to reflection holograms. Spatial modulations of both the refractive index and the absorption constant are allowed for. The effects of loss in the grating and of slanted fringes are also considered. Algebraic formulas and their numerical evaluations are given for the diffraction efficiencies and the angular and wavelength sensitivities of the various hologram types.