Optical bistability and multistability in an active interferometer.

Optoelectronic hybrid bistability and multistability in an active interferometer using a laser diode are demonstrated experimentally. The active laser-diode interferometer is composed of a Twyman-Green interferometer with an electronic feedback circuit. By feeding back the interferometer output together with an external light input through a detector to control thelaser-diode injection current, the optical bistable and multistable states of the output power from the laser diode are observed. Bistable operation does not require cutoff or saturation in the amplifier. The theoretical background of the phenomena is discussed.