Fast switching of photorefractive output by applied electric field

We show that photorefractive materials having large electro-optic coefficie nts such as BaTiO3 require relatively small electric held to induce suffici ent phase mismatch for the reduction of the diffraction efficiency to a lar ge extent. In this way Pockels effect, which is very fast, can be used to c ontrol 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 pol arized 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. (C) 2001 Pu blished by Elsevier Science B.V.