Optical bistability

rdf:langString Optical bistability

rdf:langString In optics, optical bistability is an attribute of certain optical devices where two resonant are possible and stable, dependent on the input. Optical devices with a feedback mechanism, e.g. a laser, provide two methods of achieving bistability. * Absorptive bistability utilizes an absorber to block light inversely dependent on the intensity of the source light. The first bistable state resides at a given intensity where no absorber is used. The second state resides at the point where the light intensity overcomes the absorber's ability to block light. * Refractive bistability utilizes an optical mechanism that changes its refractive index inversely dependent on the intensity of the source light. The first bistable state resides at a given intensity where no optical mechanism is used. The second state resides at the point where a certain light intensity causes the light to resonate to the corresponding refractive index. This effect is caused by two factors * Nonlinear atom-field interaction * Feedback effect of mirror Important cases that might be regarded are: * Atomic detuning * Cooperating factor * Cavity mistuning Applications of this phenomenon include its use in optical transmitters, memory elements and pulse shapers. Optical bistability was first observed within vapor of sodium during 1974.