Abstract

Nonlinear optical devices based on the intrinsic nonlinearities of a material are limited to relatively high optical intensities. Hybrid nonlinear devices using optical modulators and nonlinear electronic feedback are proposed. These devices exploit the advantages of both optical and electronic processing to generate large nonlinear properties such as bistability, programmable hysteresis responses, and control of light with light. Bulk and integrated devices can be formulated. A hybrid optical-electronic nonlinear optical device has been developed from an acoustooptic deflector with nonlinear electronic feedback controlling the acoustooptic deflector. Light from the deflector is detected and used to control a nonlinear electronic switching element. If the voltage applied to the acoustooptic device remains constant, the first-order diffracted light intensity increases linearly with increasing incident light intensity. Thus, as the input light intensity is increased, the diffracted output increases linearly as long as the detected light intensity remains below the threshold value of the electronic device. When the diffracted light signal increases above the threshold, the switch engages an electronic feedback loop which applies a variable voltage control to the acoustooptic deflector. This feedback produces nonlinearity in the optical input-output characteristic which can be adjusted electronically. By controlling the threshold intensity, hysteresis effects can be generated. An implementation of this device, including experimentally obtained bistability and hysteresis, is presented.

© 1989 Optical Society of America