One-dimensional self-focusing in photorefractive Bi12SiO20 crystal: theoretical modeling and experimental demonstration

Abstract

We have experimentally demonstrated one-dimensional self-focusing of a laser beam in a photorefractive Bi12SiO20 (BSO) crystal with an externally applied DC field. Fractional change in focal length larger than 50% was measured when the biased field was varied from 2 kV/cm to 8 kV/cm. Based on the band transport model, thin crystal approximation, and gradient index (GRIN) lens approximation, we derive a mathematical expression that describes the effect quantitatively. (C) 1999 Elsevier Science B.V. All rights reserved.