Free-space optical cross-connect switch by use of electroholography

An electrically controlled holographic switch is proposed as a building blo ck for a free-space optical interconnection network. The switch is based on the voltage-controlled photorefractive effect in KLTN crystals at the para electric phase. It is built of electrically controlled Bragg gratings store d in the volume of the crystal. A compact switch that connects four high-sp eed fiber-optic communication channels with high efficiency is demonstrated experimentally. The switch performance is investigated and optimized. This switch is extremely attractive for cascaded switching arrays such as those found in multistage interconnect networks. (C) 2000 Optical Society of Ame rica.