Optical Nonlinearities of GaAs‐Based Epitaxial Structures for All‐Optical Switching

An experimental study is made of GaAs/AlGaAs monolithic bistable etalons fabricated by metalorganic vapor‐phase epitaxy. Optical bistability is observed in the reflective mode, with a minimum threshold power of less than 3 mW and a switching contrast as high as 30: 1, with a cavity resonator designed to achieve simultaneously a high finesse and a high reflectivity contrast. The dispersive optical nonlinearity of the multiple quantum well active medium is measured as a function of the intracavity intensity, and a strong saturation behavior is observed. The origin of this saturation and its implication on the design of future devices is discussed briefly.