Abstract

We demonstrate the operation of an optical ring circuit having photorefractive gain, loss, and a photorefractive feedback coupling element that replaces a mirror of a conventional ring resonator. The feedback element serves two purposes: it compensates for resonator length changes thereby maintaining an injected signal on resonance and it also provides the circuit with a short-term memory. We present experimental results illustrating the bistable behavior of the circuit in the presence of an injected signal. Once the circuit is switched on by an injected signal it remains latched to that state in the absence of the signal for a memory time governed by the response time of the feedback element.

© 1989 Optical Society of America