The growth and studies of photorefractive Bi12TiO20 single crystals

Abstract

Photorefractive crystals of the sillenites (Bi12GeO20, Bi12SiO20, Bi12TiO20) have the promising applications in optical information processing, including spatial light modulators, optical memories, phase conjugation, image inversion, and optical interconnects.1 In comparison to other sillenities, bismuth titanium oxide (Bi12TiO20, BTO) exhibits a higher sensitivity for red lights that permit the use of a cheap HeNe laser. In addition, BTO crystals have a lower optical activity ρ, which is favourable for many applications. However, some technological problems (the incongruent melting of Bi12TiO20, the high tendency of Bi2O3-containing melts to the supercooling, etc.) created difficulties for producing large single crystals of high optical quality.