超短脉冲抽运掺铁铌酸锂的光折变效应实验研究  

Experimental Study on Photorefractive Effect of Fe：LiNb03 Induced by Ultra-Short Optical Pulse

作　　者：牛振国[1] 范薇[1] 黄大杰[1] 李国扬[1] 

机构地区：[1]中国科学院上海光学精密机械研究所高功率激光物理联合实验室,上海201800

出　　处：《光学学报》2015年第A02期252-256,共5页Acta Optica Sinica

摘　　要：对掺铁铌酸锂晶体在高功率超短脉冲激光照射下的光折变指数进行半定量的理论计算并实验验证。由理论计算得出在高功率超短脉冲激光（0．33mJ，10ps，527nm）作用下，掺铁铌酸锂晶体的折射率指数变化量达到10-4量级，在几个纳秒的弛豫时间后降低到10-5量级。实验采用同样的超短脉冲平顶激光，经过空间整形，形成空间强度分布为直角三角形的激光光束，照射掺铁铌酸锂晶体发生光折变，产生直角棱镜，使得经过瞬时光折变棱镜的1053nm脉冲信号光发生偏转，根据偏转的角度计算出的折射率指数减小量为10-5量级，理论计算与实验结果较为相符。这项研究表明利用掺铁铌酸锂晶体的瞬时光折变效应将有望实现全光条纹相机对短脉冲时间特性的测量。The photorefractive index change of iron-doped lithium niobate crystal induced by high power ultrashort pulse laser irradiation is calculated in semi-quantitative and verified in experiment. By theoretical calculations, the refractive index decrease of the iron-doped lithium niobate crystal which is induced by the high power ultrashort pulse laser （0.33 mJ, 10 ps at 527 nm） about 10-4. After the relaxation of a few nanoseconds, the index decrease is reduced to 10-s. In the experiment, the same ultrashort pulse laser is used, which is flattened and its intensity distribution is spatially shaped into a right triangle, to irradiate the iron-doped lithium niobate photorefractive crystal, resulting in rectangular prism, thus 1053 nm signal light pulse through the instantaneous photorefractive prism is deflected. The refractive index decrease calculated according to the angle of deflection is about 10 s and theoretical result is almost in agreement with experiment. This study suggests that all-optical streak camera using the instantaneous photorefractive effect of iron-doped lithium niobate is expected to achieve the measurement of time characteristics of short pulse.

关 键 词：超快光学 光折变效应 掺铁铌酸锂 光束偏转 条纹相机 

分 类 号：O436[机械工程—光学工程]