波长可调谐克尔锁模外腔面发射激光器  

Wavelength-Tunable Kerr Mode-Locked External-Cavity Surface-Emitting Laser

作　　者：曾盈莹 沈晓红 毛琳 王涛 朱仁江[1] 罗海军[1] 佟存柱[2] 汪丽杰[2] 宋晏蓉[3] 张鹏[4] Zeng Yingying;Shen Xiaohong;Mao Lin;Wang Tao;Zhu Renjiang;Luo Haijun;Tong Cunzhu;Wang Lijie;Song Yanrong;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,Jilin,China;College of Applied Sciences,Beijing University of Technology,Beijing 100124,China;National Center for Applied Mathematics,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,吉林长春130033 [3]北京工业大学应用数理学院,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：《中国激光》2022年第21期62-68,共7页Chinese Journal of Lasers

基　　金：国家自然科学基金(61904024,61975003,61790584,62025506);在渝本科高校与中科院所属院所合作项目(HZ2021007);重庆市教委科技计划重大项目(KJZD-M201900502)。

摘　　要：利用半导体增益介质中的非线性克尔效应,结合增益芯片上泵浦光斑形成的软光阑,在外腔面发射激光器中实现了重复频率为1.1 GHz、脉冲宽度为4.3 ps的连续自锁模。通过在谐振腔内插入不同厚度的双折射滤波片,实现了可连续调谐的激光波长输出。当双折射滤波片的厚度为2 mm时,获得的波长调谐范围为30 nm,最大输出功率为129 mW,激光器可在964~979 nm波段内维持连续锁模状态,获得的锁模调谐波长范围为15 nm。本文还分析了外腔面发射激光器中启动克尔锁模的机理和条件,同时就双折射滤波片对锁模激光波长的调谐范围进行了讨论。Objective Wavelength-tunable lasers have important applications, particularly in laser spectroscopy, life sciences, environmental monitoring, and information processing. Ultrashort laser pulses produced by mode-locking can be widely used in nonlinear frequency conversion, medical diagnosis, high-speed electro-optic sampling, and laser micro/nano fabrication. Wavelength-tunable mode-locked lasers combine the advantages of these two types of lasers and enable the development of multiple applications such as fluorescence excitation, laser spectroscopy, optical frequency combs, and super-resolution microscopic imaging. External-cavity surface-emitting lasers possess the advantages of both solid-state disk lasers and surface-emitting semiconductor lasers and can simultaneously produce high power with good beam quality. In this study, a wavelength-tunable Kerr mode-locked external-cavity surface-emitting laser is proposed. Wavelengthtuning and mode-locking are realized simultaneously in a linear cavity, and the output performance of the proposed approach is experimentally studied. In addition, relevant physical mechanisms involving wavelength tuning and Kerr mode locking are analyzed to understand the experimental results.Methods Using the nonlinear Kerr effect in a semiconductor gain medium and a soft aperture formed by the overlap between the pump and laser spots on the gain chip, an equivalent saturable absorber can be built into an optically pumped external-cavity surface-emitting laser. The Kerr effect forms an equivalent lens to focus the laser beam, and the soft aperture limits the transverse dimension of the laser. Their combined action, namely saturable absorption, involves selecting a pulse with sufficient strength from the intracavity noises, amplifying and shaping the selected pulse in the round-trip process, and finally maintaining a stable oscillation in the cavity and a steady output pulse train, thereby realizing continuous-wave mode-locking. Wavelength tuning of the laser was achieved by inserting a bi

关 键 词：激光器 垂直外腔面发射激光器 克尔锁模 双折射滤波片 调谐 

分 类 号：TN245[电子电信—物理电子学]