In an optical time-division switching system, time-division multiplexed calling and called station signals are arranged in incoming time slots and applied through an incoming common optical medium to a first optical switching circuit that switches the signals to optical bistable devices in which the...http://www.google.com.au/patents/US4608682?utm_source=gb-gplus-sharePatent US4608682 - Optical time-division switching system employing optical bistable devices
