Growth and optical properties of Zn:Ce:Cu:LiNbO3 single crystals

A series of congruent crystals Zn:Ce:Cu:LiNbO3 crystals doped with Zn(0, 3, 5, 7 mol%) were grown by using Czochralski method. OH− vibrational band and fundamental absorption edge were used to deduce the defect structure. Photorefractive properties were measured by two-wave coupling and light induced scattering experiments. It was found that the response and erasure time shorten with the increase of Zn doping concentration, whereas threshold intensity to optical damage of Zn(7 mol%):Ce:Cu:LiNbO3 was two orders of magnitude higher than that of Ce:Cu:LiNbO3. In this paper, site occupation mechanism of impurities were also discussed to explain the high resistance ability to optical damage and fast response speed in the Zn:Ce:Cu:LiNbO3 crystal.