Growth and Photorefractive Effect of Ti and Fe Co-doped LiNbO_3 Crystal

Ti and Fe co-doped LiNbO3 crystals were grown from the melt by Czochralski method. Theinfluence of different doping concentration on photorefractive effect was studied, the optical transmission spectra before and after reduction treatment were measured too. It was confirmed byESR method that Ti ion exists in untreated Ti: Fe: LiNbO3 crystals in the form of Ti4+. Itwas supposed that the Fe2+ concentrations increase in untreated Ti: Fe: LiNbO3 crystal due tocharge compensation effect. Without reduction treatment, the concentration of Fe2+ in crystalscan be controlled by Ti dopping. The diffraction efficiency, which can be high up to over 90.00%,was also measured by using two-wave coupling technique. Ti: Fe: LiNbO3 crystal is a good newphotorefractive material.