The speed of today"s high performance electronic computers is increasingly limited by the number and bandwidth of the interconnections and by data storage and retrieval rates rather than by processing power. Optics, with its inherent parallelism and interconnection capabilities, can offer interesting solutions to help alleviate these limitations. In the last few years, many significant advances have been made in the development of optical computing hardware. This book gives an overview of the most recent research in the following areas: device technology (SEED, VSTEP and the macrolaser devices); micro-optic components (refractive, diffractive and integrated micro-optic packaging); optical interconnections (multistage interconnection networks, reconfigurable interconnections, spot array generation); 3-D optical memory using two-photon interaction; and architecture for optical computers and photonic switching systems.