Mg:Sc:Fe:LiNbO_3晶体缺陷结构和全息存储性能  

Defect structure and holographic storage properties of Mg:Sc:Fe:LiNbO_3 crystals

作　　者：罗伟[1,2] 桂强[2] 郑威[2] 

机构地区：[1]洛阳理工学院材料科学与工程系,洛阳471023 [2]哈尔滨理工大学材料科学与工程学院,哈尔滨150040

出　　处：《功能材料与器件学报》2010年第3期233-237,共5页Journal of Functional Materials and Devices

基　　金：黑龙江省自然科学基金(E200512)

摘　　要：采用提拉法,从Li/Nb变化(0.94,1.05,1.20,1.38)的熔体中生长出Mg:Sc:Fe:LiNbO_3晶体。Li/Nb=1.05的晶体OH^-振动吸收峰在3504cm^(-1)处出现的主吸收峰,且在3466cm^(-1)、3481m^(-1)处有两附加峰。Li/Nb=1.38的晶体OH^-振动吸收峰在3535 cm^(-1)处出现附加吸收峰。红外光谱结果表示Li/Nb=1.05的晶体是近化学剂量比的,且Sc掺质优先于Mg掺质达到阈值浓度。采用透射光斑畸变法测得Mg:Sc:Fe:LiNbO_3晶体(Li/Nb=1.05)的抗光损伤能力为2.0×10~4W/cm^2,比Fe:LiNbO_3提高了三个数量级。采用波长为632.8nm的He—Ne激光器作为光源,通过二波耦合方法测试晶体全息存储性能。实验结果表明:随着Li/Nb的增加,晶体的写入时间缩短,晶体的衍射效率降低,光折变灵敏度增加,动态范围减少。在一系列晶体中,Mg:Sc:Fe:LiNbO_3晶体(Li/Nb=1.05)更加适合作为全息存储介质。Mg：Sc：Fe：LiNbO3 crystals were grown by Czochralski method from various ratios 0.94, 1.05, 1.20 and 1.38 in melt. The IR spectra were measured in order to investigate structures, the OH absorption peak of the crystals with Li/Nb = 1. 05 was 3466cm^-1, 3504cm^-1, while the OH^- absorption peak of the crystals with Li/Nb = 1. 38 was 3535cm^-1. The results indicated that the Sc concentration reaches the threshold priority. of Li/Nb = their defect 3481 cm^-1, 3504cm ^- 1, The optical damage resistance was characterized by the transmitted beam pattern distortion method. The threshold intensity of the crystals with Li/Nb = 1.05 is 2.0 × 10^4W/cm^2 , three orders of magnitude higher than that of Fe ： LiNbO3. The photorefractive properties of Mg ： Sc ： Fe ： LiNbO3 crystals were measured with He - Ne laser at the wavelength of 632.8nm by two wave coupling method. As the Li/Nb ratio increased, the diffraction efficiency and dynamic range of crystals decrease, the write time and the erasure time decrease, and the photorefraetive sensitivity increase. It has been found that, the optimal Li/Nb ratios is 1.05 among this crystal series. The effect of Li/Nb ratios on the holographic storage properties of Mg：Se：Fe： LiNbO3 crystals is discussed.

关 键 词：铌酸锂晶体 提拉法 全息存储性能 缺陷结构 

分 类 号：O734[理学—晶体学]