Diffraction properties of multiple-beam photorefractive gratings

Abstract

We have analytically solved the problem of N mutually incoherent pairs of beams in photorefractive media, each pair of which shares a common grating. The results are applied to study simultaneous read–write of dynamic photorefractive holograms with beams of comparable intensity. The diffraction efficiency is shown to be a nonlinear function of the read-beam intensity and is nonreciprocal with respect to readout from the two input ports. A complete energy transfer between the two write beams occurs in a finite thickness of the photorefractive crystal, in contrast to the infinite thickness required in the standard two-beam coupling case.