IMPROVEMENT OF PHOTOREFRACTIVE PROPERTIES OF PROTON-EXCHANGED LITAO3 WAVE-GUIDES

Photorefractive planar waveguides in LiTaO3 are fabricated by both a p roton exchange and a successive copper exchange. The influence of diff erent fabrication steps on the refractive index profile and optical ab sorption is investigated. The holographic efficiency is determined tog ether with the dark-and photo-conductivity. We show that the photorefr active properties of proton-exchanged LiTaO3 waveguides are considerab ly improved by the additional copper exchange. It is established that the holographic efficiency depends on the copper content, the phase of the proton-exchanged layer and the light intensity.