Analysis of light wave diffraction and amplification by reflection grating operating in the second-order Bragg regime. 1. Approximate theory

摘要

A new approximate theory was developed and applied to analysis of the second-order Bragg diffraction by a thick reflection grating formed in a medium with and without optical gain. To derive the general system of equations describing the optical wave interaction with a grating, the method of variation of constants was used, which allowed us to obtain the analytical formulas for the electric-field strength of transmitted and reflected waves. The proposed approach was extended to the case of grating formed in a material with nonlinear response to the recording field when dielectric permittivity modulation of a medium includes higher spatial harmonics.