Description : Research in optical information technology in Europe has been very active inrecent years. This volume records state-of-the-art research conducted in some 22 laboratories who have worked together within EC ESPRIT Basic Research Action 3199 up to 1992. The topics cover: (1) Active optical logic and switching devices - embracing new materials, nonlinear and electrooptic mechanisms as well as advanced device fabrication. These devices cover the range from all-optical nonlinear interferometer structures through hybrid optical-electronic modulators to integrated emitter-receiver structures. (2) The latest state of optical interconnect technology, embracing diffractive optics (binary and multi-level phase gratings), holographic space-variant elements and micro-refractive optics. (3) Contributions on optical information processing architecture and demonstrator projects. The materials base ranges from silicon to II-VI materials with the realisation of pn-junction devices in ZnSe. The research reported here lays the basis for long-term progress in devices for information processing.