A new acoustophotorefractive effect in lithium niobate

Abstract

A new photorefractive effect resulting from the interaction of high‐intensity short‐duration laser pulses with propagating acoustic waves has been found to occur in LiNbO₃. The index‐of‐refraction change (δn) is proportional to the rf signal and increases sublinearly with the number of laser pulses and as the 1.3 power of the incident laser energy density (J) per pulse. The decay time of δn varies from a few hours when only green illumination (530 nm) is used to several weeks when combined green and infrared illumination (1060 nm) are used. This acoustophotorefractive effect can be utilized to construct an acousto‐optic memory correlator.