Selective enhancement of spatial harmonics of a photorefractive grating

Abstract

We demonstrate a technique by which the amplitudes of the various spatial harmonics of a holographic grating written in a photorefractive material may be increased with respect to one another. We show that for holographic recording with a moving intensity grating, the grating velocity may be chosen so as to amplify selectively a given spatial harmonic. This result is derived analytically and tested by measurements of the first three spatial harmonics of a grating written in a photorefractive Bi12SiO20 crystal.