Characteristics of the photorefractive effect in Bi2TeO5

Bismuth tellurite (Bi2TeO5) is a new photorefractive material that is now available as single crystals of high optical quality. The results of measuring the photorefractive properties of Bi2TeO5 crystals are reported and the properties of this material are compared to those of well known photorefractive crystals. The decay of the photorefractive signal in Bi2TeO5 has multiple components and several different contributions to this signal were identified. One of the components has a lifetime of months and therefore has potential for holographic memory applications. This long-lived photorefractive signal is attributed to ion displacements and it can be produced by both continuous wave and short pulse write beams. Several experimental conditions were investigated to enhance this photorefractive signal.