Experimental photonic time-slot interchanger using optical fibers as reentrant delay-line memories

An experimental system has been designed and built that interchanges digital data from time slots in its input to time slots in its output. The data are carried by optical fibers, are switched by Ti:LiNbO3 directional couplers,1 and remain in photonic form throughout. The format is a series of frames, each with a start-bit and N sequential time slots. Thus the system is an N × N time-division switch.