Cu:KNSBN晶体生长及其光折变效应的研究

Study on Growth and the Photorefractive Effect of Cu:KNSBN Crystal

在KNSBN晶体中掺进CuO,采用硅钼棒作加热体,以Czochralsk i技术生长Cu:KNSBN晶体。以二波耦合光路,测试晶体的衍射效率和记录时间,计算折射率变化值Δn。Cu:KNSBN晶体的衍射效率,记录速度和折射率变化值皆高于Fe:L iNbO3晶体。尤其记录速度比Fe:L iNbO3晶体高一个数量级以上。测试Cu:KNSBN晶体位相共轭反射率R和自泵浦位相共轭反射率RC。Cu:KNSBN晶体的自泵浦位相共轭反射率RC值达到64%,是纯KNSBN晶体的二倍。以Cu:KNSBN晶体自泵浦位相共轭镜进行消畸变实验。实验结果表明:输出光波确系输入探测光波的位相共轭光波。

Doping with CuO in the KNSBN crystal and using Si-Mo rod as heater,the Cu：KNSBN crystal was grown by Czochralski technique. The diffraction efficiency（η） and recording time τw were measured by two-wave coopling light path and the refractive index change value An was calculated. The diffraction efficiency （η）, recording speed and refractive index value △n were higher than that of Fe： LiNbO3 crystals. The recording speed of Cu ： KNSBN crystal was one order of magnitude higher than that of Fe ： LiNbO3 crystal. The phase conjugate reflectivity R and self-pumped phase conjugate reflectivity Rc were measured. The self-pumped phase conjugate reflectivity Rc of Cu ： KNSBN crystal reached 64%, which was two times the pure KNSBN crystal. Eliminating distortion experiment was carried out by using selfpumped phase conjugation mirror. The experimental results indicate that the output beam determination is a phase conjugate beam of input probe beam.