FAST PHOTOREFRACTIVE MATERIALS USING QUANTUM-WELLS

Photorefractive materials utilizing the large electro-optic coefficients of quantum wells are attractive for image processing applications due to the potentially fast response times (less than mu s). Recent results on photorefractive quantum wells indicate that lateral diffusion of trapped carriers is a serious limitation of the spatial resolution. In order to address this problem, we propose the incorporation on either side of a multiple quantum well section, of ultrathin layers of InAs islands serving as a dense layer of deep traps eliminating lateral diffusion. Furthermore, we propose a novel quantum heterostructure especially designed to be used as a thin film photorefractive device without the need of electrical contacts.