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.

© 1994 IEEE