Optimization Of Photorefractive Sillenites

Abstract

Impurity doping of bismuth germanium oxide (BGO) has been found to yield large impovements in the photorefractive sensitivity (S1). A 17 fold increase over BGO has been obtained with fully titanium substituted BGO. This improvement is manifested as a simultaneous enhancement of the saturation diffraction efficiency and reduction of the characteristic time constant of the material. We suggest that the former arises from an increase in the effective electrooptic coefficient though the mechanism giving rise to the reduced time constant is as yet unknown.