利用Cr4+∶YAG晶体的各向异性提高输出激光消光比的实验研究  

Improving Extinction Ratio of Output Laser with Anisotropy of Cr4+… YAG Crystal

作　　者：张思 汪楠[2] 王旭葆[1] 林学春[2] Zhang Si;Wang Nan;Wang Xubao;Lin Xuechun(Institute of Laser Engineering,Beijing University of Technology,Beijing100124,China;Laboratory of All-Solid-State Light Sources,Institute of Semiconductors,Chinese Academy of Sciences, Beijing 100083,China)

机构地区：[1]北京工业大学激光工程研究院,北京100124 [2]中国科学院半导体研究所全固态光源实验室,北京100083

出　　处：《激光与光电子学进展》2019年第16期137-141,共5页Laser & Optoelectronics Progress

基　　金：中国科学院科研装备研制项目(GJJSTD20180004)

摘　　要：为了研究不同切割方向Cr4+∶YAG晶体的各向异性对激光器输出偏振特性的影响,采用1064nm线偏振脉冲光作为测试光源,从输入光强功率密度、晶体初始透过率和晶体切割方向3个方面,对Cr4+∶YAG晶体的各向异性进行实验研究。结果表明:在一定功率密度范围内,功率密度越高,Cr4+∶YAG的各向异性越明显;Cr4+:YAG的初始透过率越低,各向异性越明显;相同功率密度下,[110]切割方向的Cr4+∶YAG在某一方向上的可饱和透过率大于[100]切割方向的Cr4+∶YAG的透过率。分别选取[110]和[100]切割方向的Cr4+∶YAG作为调Q晶体,搭建808nm LD抽运Nd∶YAG/Cr4+∶YAG被动调Q固体激光器,得到[110]切割方向Cr4+∶YAG的输出激光消光比大于[100]切割方向Cr4+∶YAG的输出激光消光比。To explore the effect of the anisotropy of different cut directions of Cr4+: YAG crystals on the polarization characteristics of laser output,the anisotropy of Cr4+: YAG crystal is studied experimentally using1064-nm linearly polarized pulsed light as the test light source.In the experiment,the input light power density,initial transmittance,and crystal cutting direction are considered.The experimental results demonstrate that within a certain range of power density,the higher the power density is,the more obvious the anisotropy of Cr4+: YAG is.The results also show that anisotropy is obvious with low initial transmittance of Cr4+: YAG.Under the same power density,the saturation transmittance of[110]-cut Cr4+: YAG is greater than that of[100]-cut Cr4+:YAG in a certain direction.The[110]-cut and[100]-cut Cr4+: YAG crystals are used as saturable absorbers for an 808-nm LD pumped passively Q-switched Nd∶YAG/Cr4+∶YAG solid laser,and the experimental results demonstrate that the extinction ratio of the output laser with[110]-cut Cr4+:YAG is greater than that with [100]-cut Cr4+: YAG.

关 键 词：激光器 被动调Q Cr4+∶YAG 各向异性 

分 类 号：TN248.1[电子电信—物理电子学]