Self-induced photorefractive spatial frequency filter

Abstract

A Bi12SiO20 crystal, cut in the transverse orientation as for holographic applications, is used as a spatial filtering device in the Fourier plane of a coherent single-beam optical processor with λ = 633 nm. Frequency selection is obtained by adjusting a polarizing compensator to suppress or to select some part of the spectrum, which is characterized by a certain ellipticity of polarization, depending on its intensity.