All-optical flip-flop operation in an optical bistable device using two lights of different frequencies

All-optical flip-flop operation in a Fabry-Perot-type optical bistable device (OBD) is investigated. The OBD is switched both from OFF to ON and ON to OFF using two lights of different frequencies as trigger pulses. We present the theoretical calculation, obtained by applying a conventional expression for a dispersive OBD to the two-light input case, and the experimental observation, in which a semiconductor laser amplifier is used as a bistable device.