Reflection holographic gratings formation in Bi12TiO20 crystal

The processes of a space-charge grating formation in photoconductive materials, particularly in photorefractive crystals, have now attracted considerable interest. A majority of the investigations treating two-beam interaction have considered the codirectional geometry. A reflection grating in the (111) cut of Bi₁₂TiO₂₀ (BTO) crystal was demonstrated previously as useful for real-time dynamic holographic interferometry. The polarization properties of self-diffraction in the reflection geometry for a (001) cut of selenite crystals have been analyzed by Mallick et al. (1997). In this paper, the authors report the temporal behavior of light beams interacting on photorefractive reflection gratings in a nominally pure BTO crystal. The time evolution of light-induced absorption and two-beam coupling gain is investigated experimentally and theoretically