Fast switching of photorefractive output by applied electric field

Abstract

We show that photorefractive materials having large electro-optic coefficients such as BaTiO 3 require relatively small electric field to induce sufficient phase mismatch for the reduction of the diffraction efficiency to a large extent. In this way Pockels effect, which is very fast, can be used to control the diffraction efficiency in photorefractive wave mixing. The fast switching effect is shown in both two-wave mixing and four-wave mixing (FWM) geometries. We also show that optical switching based on orthogonally polarized photorefractive FWM has certain important advantages over that based on FWM with all extraordinary waves. This phenomenon can be very useful in fields like free space optical switching and interconnections.