Abstract: A circuit plane or "board" includes a plurality of optical-micro-circuit device sockets with optical interface windows around the periphery of each socket. Each socket is adapted to receive a wafer or like component which comprises an electrical micro-circuit having optical input and output devices at the periphery of which register with the interface windows of the socket. The windows are optically interconnected with optical interface windows of other sockets or with optical terminals along the edge of the "board" by means of optical fibers embedded in a potting material typically sandwiched between two thermally and electrically conductive plates. Operating power for the circuits is applied to the conductive plates to which the micro-circuits are electrically coupled. A plurality of circuit boards so formed can be stacked on one another and optically coupled by means of light transmitting end connectors including optical fibers therein to form a complete data processing system.