Photorefractive response and optical damage of LiNbO3 optical waveguides produced by swift heavy ion irradiation

The photorefractive behaviour of a novel type of optical waveguides fabricated in LiNbO₃ by swift heavy ion irradiation is investigated. First, the electro-optic coefficient r ₃₃ of these guides that is crucial in the photorefractive effect is measured. Second, two complementary aspects of the photorefractive response are studied: (i) recording and light-induced and dark erasure of holographic gratings; (ii) optical beam degradation in single-beam configuration. The main photorefractive parameters, recording and erasing time constants, maximum refractive-index change and optical damage thresholds are determined.