Abstract

Semiconductor photorefractive quantum well devices are prime candidates for high speed real-time image processing applications because of their high speed, small thickness and large electro-optic nonlinearities¹,²,³. When used in the Stark geometry, where a field is applied perpendicular to MQW layers, the optical nonlinearity arises from longitudinal field screening in the illuminated areas. Lateral spatial modulation of the field screening is translated to lateral spatial modulation of refractive index and absorption by the quantum confined Stark effect. Device performance is characterized by spatial resolution and sensitivity, both of which strongly depend on carrier transport. The spatial resolution decreases with increased lateral carrier transport⁴,⁵, while the sensitivity increases with increased longitudinal transport. Highly trapping materials have been successfully used to increase the device resolution down to 5-7 μm⁶,⁷.

© 1997 Optical Society of America