Nonlinear optical element and method of using the same

摘要

According to the present invention, there is provided a nonlinear optical element including a p-i-n type photodiode (i layer is a light absorbing layer) provided with a barrier layer preventing the going-through of a majority carrier. In the nonlinear optical element of the present invention, since the charges are accumulated with the stop of carrier moving, there occur a deformation in energy band and change in internal electric field. Optical bistability can be attained even without an external circuit. Further, with a plurality of incident light, only one element can exhibit optical bistability therefor because there is no need to dispose an external circuit. According to a method of the present invention, it is possible to control bistability for one light by overlapping another light input to a carrier diffusing region generated by the one light.