Orthogonal Two-Wave Vector Interaction in a Gyrotropic Photorefractive Crystal

We have proposed and tested a new scheme of organization of an adaptive interferometer, which is based on the orthogonal geometry of the two-wave vector interaction in a gyrotropic photorefractive crystal. The mathematical model developed here makes it possible to calculate the efficiency of the two-wave interaction in a gyrotropic photorefractive crystal in the orthogonal geometry. The model is used to determine the conditions in which the regime of polarization independence of the additive interferometer is realized. It is shown that the polarization independence is attained due to the natural rotation of the polarization plane of light waves in a crystal, which is caused by optical gyrotropy. The key feature of the approach developed here is the possibility of attaining such a regime using only one reference wave in contrast to other analogous methods, in which two reference waves are required; this makes it possible to substantially simplify the design of the adaptive interferometer.