Mg^(2+)对Ce:Fe:LiNbO_3晶体光折变性能的作用和影响

Effect and Influence of Mg^(2+) on Photofractive Properties of Ce∶Fe∶LN Crystals

在Ce(0 .1wt %)∶Fe(0 .08wt %)∶LN中掺进摩尔分数为(0 .2 %,0 .4 %,0 .6 %)的MgO,采用提拉法生长Mg∶Ce∶Fe∶LN晶体.测试晶体的吸收光谱,Mg∶Ce∶Fe∶LN晶体的吸收边相对Ce∶Fe∶Li NbO3晶体发生紫移,Mg(6 %)∶Ce∶Fe∶LN晶体OH-吸收峰移到3 532 cm-1,研究OH-吸收峰移动机理.以二波耦合光路测试Mg∶Ce∶Fe∶LN晶体的指数增益系数和响应时间,发现Mg∶Ce∶Fe∶LN晶片厚度减小时指数增益系数显著增加.首次采用光爬行效应解释指数增益系数增加机理.

Doping with （0.2%,4%,6%）（in mole） MgO in Ce（0. 1wt%） ： Fe（0.07wt%） ： LN,Mg ： Ce： Fe： LN crystals have been grown by czochralski method. The infrared spectra of crystals were measured. The OH^- absorption peak of Mg（6%） ： Ce ： Fe： LN crystal shifts to 3 532 cm^-1. The shift mechanism was studied The exponential gain coefficient and response time of Mg ： Ce ： Fe ： LN crystals were measured by two wave coupling light path. When the thickness of crystal plate of Mg ： Ce ： Fe ： LN reduces, the exponential gain coefficient increases notablely. Light crawling effect is adopted to explain the enhancement mechanism of expontial gain coefficient.