Theory and applications of four-wave mixing in photorefractive media

TLDR

Four‑wave mixing theory in photorefractive crystals is developed. The study demonstrates photorefractive crystals as optical distortion correction elements using passive phase conjugate mirrors. The theory is solved analytically under undepleted‑pump and negligible‑absorption approximations, treating transmission and reflection gratings separately. The analysis predicts reflectivities and thresholds for phase conjugate mirrors, and experiments confirm their performance.

Abstract

The development of a theory of four-wave mixing in photo-refractive crystals is described. This theory is solved in the undepleted pumps approximation with linear absorption and without using the undepleted pumps approximation for negligible absorption. Both the transmission and reflection gratings are treated individually. The results are used to analyze several photorefractive phase conjugate mirrors, yielding reflectivities and thresholds. The use of photorefractive crystals as optical distortion correction elements and experimental demonstrations of several of the passive phase conjugate mirrors are described.