平行平面腔光学参量振荡器失谐特性实验研究  

Characteristics of Mirror Misalignment of Plane-Parallel Cavity-Based Optical Parametric Oscillators

作　　者：付俏俏 刘鹏翔 祁峰[1,2,4] 李惟帆 牛春草 李伟 郭丽媛[1,2] 汪业龙 刘朝阳 Fu Qiaoqiao;Liu Pengxiang;Qi Feng;Li Weifan;Niu Chuncao;Li Wei;Guo Liyuan;Wang Yelong;Liu Zhaoyang(Shenyang Institute of Automation,Chinese Academy of Sciences,Shenyang 110169,Liaoning,China;Key Laboratory of Liaoning Province in Terahertz Imaging and Sensing,Shenyang 110169,Liaoning,China;College of Information Engineering,Shenyang University of Chemical Technology,Shenyang 110142,Liaoning,China;Institutes for Robotics and Intelligent Manufacturing,Chinese Academy of Sciences,Shenyang 110169,Liaoning,China;University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]中国科学院沈阳自动化研究所,辽宁沈阳110169 [2]辽宁省太赫兹成像与感知重点实验室,辽宁沈阳110169 [3]沈阳化工大学信息工程学院,辽宁沈阳110142 [4]中国科学院机器人与智能制造创新研究院,辽宁沈阳110169 [5]中国科学院大学,北京100049

出　　处：《中国激光》2022年第24期149-154,共6页Chinese Journal of Lasers

基　　金：中国科学院青年创新促进会资助项目(2019204);辽宁省“兴辽英才”计划(XLYC200774);沈阳市中青年科技创新人才项目(RC200512)。

摘　　要：纳秒脉冲泵浦的平行平面腔光学参量振荡器(OPO)是一种便捷的相干光源,适用于指定波长范围内的不间断调谐输出。作为一种临界腔,平行平面腔对腔镜准直角度的扰动较为敏感。本文以532 nm绿光泵浦KTiOPO4晶体临界相位匹配OPO为例,定量研究了这类光谐振腔的失谐特性。通过在理想准直位置附近扫描腔镜的偏角,观察了OPO输出随失谐角的变化。结果表明:该谐振腔对临界方向失谐的敏感程度远高于对非临界方向失谐的敏感程度;扩宽泵浦光束和提高泵浦光强都可以增大对准容限。此外,本文分析并解释了不同条件下OPO腔长对腔镜对准容限的影响。Objective Optical parametric oscillators(OPOs)have been proven to be effective,coherent light sources that can expand the wavelengths of commercial lasers(typically limited to narrow emission lines and bands)to a broad range from visible to far-infrared bands.Q-switched lasers with high peak powers have significantly promoted the development and applications of OPOs with the following advantageous characteristics:system compactness(for example,two cavity mirrors and a nonlinear crystal),relatively high conversion efficiency,singly resonant operation,and frequency-agile tunability(for example,angle tuning).A plane-parallel cavity with a large mode volume is well-suited for Q-switched laser pumps.This type of OPO is widely adopted,for example,as a pump/seed source in nonlinear terahertz or mid-infrared(MIR)generation or directly as an MIR source,owing to the wide tuning range and ease of construction.As the earliest configuration in a laser resonator,a plane-parallel cavity is critically stable and sensitive to mirror misalignment.The misalignment of laser cavities,including those of argon ion,CO2,and Nd∶YAG lasers,has been analyzed previously;however,studies on OPO cavities have rarely been reported.In this study,we performed an experimental investigation on the misalignment characteristics of a plane-parallel cavity-based OPO.Methods In this study,an OPO based on a plane-parallel cavity structure was developed.A potassium titanyl phosphate(KTP)crystal was utilized as the nonlinear medium(cut atθ=60°,φ=0°,and 10 mm×7 mm×20 mm,antireflection(AR)-coated at 532 nm/800-900 nm/1300-1600 nm).A frequency-doubled Nd∶YAG laser(532 nm,10 ns,and 10 Hz)was employed as the pump source.Two flat mirrors(AR-coated at 532 nm/1300-1600 nm and highly reflection-coated at 800-900 nm)formed a singly resonant cavity.The ns-pulsed OPO was operated at a wavelength of 1514 nm via o→e(signal)+o(idler)critical phase matching.The cavity mirrors were precisely controlled using piezoelectric optical mounts for alignment.Each mount

关 键 词：非线性光学 光学参量振荡器 平行平面腔 对准容限 临界相位匹配 

分 类 号：O437[机械工程—光学工程]