Compact photorefractive correlator for robotic applications.

We design, implement, and test a multichannel photorefractive optical joint transform correlator that is capable of performing sorting tasks for robotic applications. The use of mini-YAG lasers and liquid-crystal spatial light modulators, in conjunction with updatable holographic BSO crystals, results in a compact correlator (600 mm x 300 mm x 300 mm) with real-time capabilities (100-ms recognition speed). Flexibility is a built-in feature, and correlation is demonstrated for various applications. Electronic and optical preprocessing and postprocessing for improving demonstrator performances are also discussed.