Abstract

We have determined that sufficiently intense light passing through photorefractive crystals such as barium titanate BaTiO₃ and strontium barium niobate Sr_xBa_1−xNb₂O₆ will be thermally self-focused and self-phase modulated in much the same observed with light of extraordinary polarization traveling along an a axis. More than ten diffraction rings were observed with a 1.8-W 3-mm diam Gaussian beam from a 488-nm Ar-ion laser. The experimental parameters, such as number of diffraction rings, focal length, and angular divergence, as a function of laser intensities and at different optical wavelengths were also studied.

© 1985 Optical Society of America