Optical properties of Bi12TiO20 doped with Al, P, Ag, Cu, Co and co-doped with Al+P single crystals

Large optically homogeneous photorefractive Bi12TiO20 (BTO) single crystals doped with Al, P, Ag, Cu, Co and Al + P-co-doping were obtained by the Top Seeded Solution Growth Method (TSSG) in a Bi2O3 solution. A strong bleachi ng effect was observed for the Al, P, Ag and Al + P-doped crystals, whereas doping with Cu and Co induced a strong photochromic effect and increased t he absorption coefficients in the red spectral region. Al, P, Al + P-doped crystals increased the values of optical rotator power, while Cu and Ag-dop ed crystals exhibited a strong decrease in optical activity in comparison w ith non-doped BTO. The influences of doping elements on the optical rotatio n power are discussed on the basis of two structural elementary cell units - MO4 tetrahedra and BiOn polyhedra. (C) 2000 Published by Elsevier Science B.V. All rights reserved.