Method and apparatus for increasing the processing capacity of optical

Abstract

An optically bistable device, such as a symmetric self electro-optic effect device (S-SEED), is forced into a metastable state prior to the incidence of an optical input signal thereto, thereby increasing the sensitivity of the optically bistable device to the optical input signal, reducing both the switching time and the optical input signal energy required to switch the device. The metastable state is entered into by one of three techniques: (1) turning off the bias voltage V.sub.0 of the device with optical bias beams on then turning on the bias voltage V.sub.0 with the optical bias beams off; (2) applying a predetermined voltage to a node in the device, the predetermined voltage being substantially the metastable state voltage or V.sub.0 /2; or (3) subjecting the device to equal intensity optical bias beams having a wavelength longer than the exciton wavelength. In the second case, optical bias beams and optical input signal beams may be applied simultaneously with the application of the predetermined voltage. In the last case, optical bias beams (at the exciton wavelength) and the optical input signal beams can be applied simultaneously after removal of the long-wavelength optical bias beams, thus saving switching time. In addition, the optically bistable device may be selectively placed in the metastable state and the optical input signal have sufficient energy to switch the device only when it is in the metastable state. This allows for multiple optically bistable devices to be selectively responsive to a common optical input signal, such as in a demultiplexer.