基于外腔面发射激光器腔内三倍频的可调谐紫外激光器  

Tunable ultraviolet laser based on intracavity third harmonic generation of external cavity surface emitting laser

作　　者：成佳 伍亚东 晏日 彭雪芳 朱仁江[1] 王涛 蒋丽丹[1] 佟存柱[2] 宋晏蓉[3] 张鹏[4] Cheng Jia;Wu Ya-Dong;Yan Ri;Peng Xue-Fang;Zhu Ren-Jiang;Wang Tao;Jiang Li-Dan;Tong Cun-Zhu;Song Yan-Rong;Zhang Peng(College of Physics and Electronic Engineering,Chongqing Normal University,Chongqing 401331,China;Changchun Institute of Optics,Fine Mechanics and Physics,Chinese Academy of Sciences,Changchun 130033,China;Faculty of Sciences,Beijing University of Technology,Beijing 100124,China;National Center for Applied Mathematics in Chongqing,Chongqing Normal University,Chongqing 401331,China)

机构地区：[1]重庆师范大学物理与电子工程学院,重庆401331 [2]中国科学院长春光学精密机械与物理研究所,长春130033 [3]北京工业大学理学部,北京100124 [4]重庆师范大学,重庆国家应用数学中心,重庆401331

出　　处：《物理学报》2024年第8期115-122,共8页Acta Physica Sinica

基　　金：在渝本科高校与中国科学院所属院所合作项目(批准号:HZ2021007);重庆市教委科技计划重大项目(批准号:KJZDM201900502);重庆市教委科技计划(批准号:KJQN202200557,KJQN202300525);国家自然科学基金面上项目(批准号:61975003,61790584,62025506);重庆师范大学基金(批准号:23XLB003)资助的课题.

摘　　要：紫外激光器具有频率高、波长短、单光子能量大以及空间分辨率高等特点,在精细加工、生命科学、光谱学等许多方面应用前景广阔.本文报道了一种基于外腔面发射激光器腔内三倍频的可调谐紫外激光器.该激光器采用了W型谐振腔,并插入双折射滤波片作为偏振和波长调谐元件,通过Ⅰ类相位匹配的LBO晶体对980 nm基频光进行倍频产生490 nm蓝光,再通过Ⅰ类相位匹配的BBO晶体对9.80 nm基频光和490 nm倍频光进行和频获得327 nm紫外输出.当LBO和BBO晶体的长度都为5 mm时,在环境温度为15℃,泵浦功率为47 W的条件下,实验输出的327 nm紫外激光功率达到538 mW.选择厚度为2 mm的双折射滤波片作为调谐元件,可获得的紫外激光器输出波长的连续调谐范围为8.6 nm.该紫外激光器同时显示了良好的光束质量和较好的功率稳定性.Ultraviolet laser has high frequency,short wavelength,large single-photon energy,and high spatial resolution,and has wide applications in many fields such as fine processing,life sciences,and spectroscopy.In this work,a wavelength tunable ultraviolet laser based on intracavity third harmonic generation from an external-cavity surface-emitting laser is reported.The W-type resonant cavity of the laser is composed of a distributed Bragg reflector(DBR)at the bottom of the gain chip,three plane-concave mirrors,and a rear plane mirror.On the arm containing the gain chip,a birefringent filter is inserted at the Brewster angle as the polarization and wavelength tuning element,which can also narrow the linewidth of the fundamental laser to a certain extent.A type-Ⅰ phase-matched LBO crystal is placed on the beam waist between the folding mirrors M2 and M3 to convert the 980 nm fundamental laser into 490 nm blue light,and a type-Ⅰ phase-matched BBO crystal is inserted in the beam waist near the rear mirror to produce a 327 nm ultraviolet output from the remained 980 nm fundamental laser and the frequency-doubled 490 nm second harmonic.Before the BBO crystal,a half-wave plate at 980 nm is employed to change the polarization of the fundamental laser,so as to meet the type-Ⅰ phase-matching condition of the used BBO crystal.Owing to the larger nonlinear coefficient of the type-Ⅰ phase-matched BBO crystal,and its obviously higher transmittance at 327 nm wavelength than the usually used LBO crystal,the output power is obtained to be 538 mW at 327 nm ultraviolet wavelength,corresponding to a conversion efficiency of 1.1% from pump light to ultraviolet laser.The experiment is performed under conditions of 15℃ temperature,47 W absorbed pump power,5 mm-length LBO and 5 mmlength BBO crystals.By using a 2 mm-thick birefringent filter as the tuning element,34.1 nm tuning range of the 980 nm fundamental laser,14.3 nm tuning range of the 490 nm second harmonic,and 8.6 nm tuning range of the 327 nm third harmonic are obtained.Th

关 键 词：可调谐 外腔面发射激光器 非线性频率变换 三倍频 

分 类 号：TN248[电子电信—物理电子学]