Fixed index gratings in LiNbO3 : Fe upon long-term exposure to an intense laser beam

Abstract

Permanently fixed noisily recorded refractive index gratings are discovered in single crystals of LiNbO3: Fe upon long-term exposure to a single laser beam with high intensities of I= 100 kW/m(2) and ambient temperature. The fixing process is explained by considering the effect of laser-induced heating of the sample and the well-known simultaneous thermal fixing procedure. (c) 2007 Optical Society of America.