Coupling Between Transmission and Reflection Gratings in Photorefractive Phase Conjugators

Abstract

In most derivations of the reflectivity of a photorefractive phase conjugator, the contributions from the transmission grating and reflection grating are assumed to be independent. This is in general not correct We show that within the undepleted pump approximation, the transmission and reflection gratings can couple through a grating formed by the two counter-propagating pump waves. We present a general linearized theory including this coupling and show that it significantly alters the response.