Mode Degradation by Photorefractive Damage in Planar Optical Waveguides

Electrooptic materials, particularly LiNbO3, are used to fabricate optical waveguides and a variety of integrated optics devices1. However, the performance of this devices is hampered by the light-induced change in refractive index which leads to mode degradation. This damage or photorefractive effect (PRE) has been extensively investigated2 for LiNbO3 and a number of experiments have dealt with mode degradation in waveguides3,4,5. However, the theoretical description of these phenomena is in a very preliminary and insatisfactory stage.