An experiment on high-speed optical time-division switching

An experimental high-speed optical time-division switching system has been realized. The system is able to exchange digitally encoded color video signals at 256-Mbit/s highway speed. Bistable laser diodes and directional coupler switch matrices are adopted as optical memories and optical read/write gates, respectively, in an optical time switch. The bistable laser diode operates as an optical flip-flop circuit which can be set and reset by optical and electrical signals, respectively. 256-Mbit/s highway speed has been realized with sufficient input highway operating margin using the same wavelength as that of bistable laser diodes for an electrooptical converter. Results of this experiment will be helpful data for use in constructing future optical telecommunications networks, where a variety of broad-band services need to be realized.