Photorefraction in LiNbO3:Fe crystals with femtosecond laser pulses

The photorefractive effect in lithium niobate crystals (LiNbO₃) is investigated using femtosecond (fs) laser pulses. Photorefractive effect can destroy the beam profiles and the phase matching conditions due to "optical damage" and "light-induced scattering". The aim of the work presented here is to look for similarities and differences in the photorefractive effect for pulsed and cw illumination at 532 nm wavelength. Elementary holographic gratings are written with different light polarizations and average intensities into as-grown and oxidized iron-doped LiNbO₃ crystals. The writing beam is split in two beams of approximately equal power.