2-WAVE AND INDUCED 3-WAVE MIXING ON A THIN BI12TIO20 HOLOGRAM

Wave mixing in thin holograms in Bi12TiO20 was studied. The adaptive i nterferometric technique involving phase modulation of one of the inci dent beams was used. It was shown that not only two-wave, but also thr ee-wave and even multiwave mixing, can be detected in thin holograms i n case of nonlinear holographic recording. Trap saturation was found t o play an important role in the spatial frequency and external field d ependences of a two-wave mixing signal because of spatial phase shift between the interference pattern and holographic grating.