Near-field spatial light modulator based on photoinduced hexagonal array of waveguides

Summary form only given. There is a great need of fast temporal-spatial light modulators (TSLMs) for optical processing using coherent beams. Here we suggest another scheme of fast TSLM based on photoinduced hexagonal array of photorefractive waveguides. It was found, that in some thick photorefractive crystals, counterpropagating laser beams in the presence of a scattering seed develop highly regular hexagonal arrays both in the near and far fields. This phenomenon observed in a 1-cm-thick photorefractive crystal KNbO/sub 3/ was explained as the formation of self-induced waveguides, which create the near-field hexagonal pattern by optical channeling.