The study of optically bistable devices and their generic characteristics has received increased attention in the scientific community.  See, for example, the special issue on optical bistability IEEE Journal of Quantum Electronics, QE-17, March 1981.  Bistable optical devices are often classified into one of two categories.  In the first category are intrinsic devices which are those devices in which the feedback required for bistability is optical.  In the second category are hybrid devices in which devices some form of electrical feedback, sometimes in conjunction with optical feedback, is used.  Intrinsic devices are of particular interest because of their potential for ultra-fast switching. 
Many of the intrinsic devices known in the prior art require resonant optical cavities.  As a result of this characteristic, these prior art intrinsic devices require that the input light to the device be tuned to a special frequency.  In addition, these devices are frequently sluggish in their operation due to the long lifetimes associated with their high-finesse cavities.  It is expected that the operation of an intrinsic optically bistable device could be improved if the device did not require a resonant cavity.