Nonlinear refraction, nonlinear absorption and optical limiting in BSO and BGO photorefractive crystals

摘要

This paper presents experimental results on nonlinear refraction, nonlinear absorption and optical limiting in photorefractive crystals Bi_(12)SiO_(20) (BSO) and Bi_(12)GeO_(20) (BGO) at the fundamental and second harmonic wavelengths of picosecond Nd:YAG laser radiation. It is shown that nonlinear refraction was due self-focusing process when nonlinear absorption was due to three-photon absorption at the wavelength of 1064 nm and two-photon absorption at the wavelength of 532 nm.