67 MHz超低重复频率锁模外腔面发射激光器  

67 MHz Ultralow Repetition Rate Mode-Locked External-Cavity Surface-Emitting laser

作　　者：张佳琦 贺亮 朱仁江[1] 王涛 蒋丽丹[1] 蒋茂华[1] 佟存柱[2] 宋晏蓉[3] 张鹏[4] Zhang Jiaqi;He Liang;Zhu Renjiang;Wang Tao;Jiang Lidan;Jiang Maohua;Tong Cunzhu;Song Yanrong;Zhang Peng(College of Physics and Electronic Engineering,Chongqing Normal University,Chongqing 401331,China;State Key Laboratory of Luminescence and Applications,Changchun Institute of Optics,Fine Mechanics and Physics,Chinese Academy of Sciences,Changchun 130033,Jilin,China;College of Physics and Optoelectronic Engineering,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发光学及应用国家重点实验室,吉林长春130033 [3]北京工业大学物理与光电工程学院,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》2025年第2期72-80,共9页Chinese Journal of Lasers

基　　金：国家自然科学基金(61975003,61790584,62025506);在渝本科高校与中国科学院所属院所合作项目(HZ2021007);重庆市教委科技研究计划(KJQN202200557,KJQN202300525);重庆师范大学人才引进/博士点基金(23XLB003)。

摘　　要：垂直外腔面发射激光器(VECSEL)具有高功率、高光束质量、波长可根据实际需要进行设计等独特优点,应用场景十分丰富。锁模VECSEL产生的高峰值功率脉冲能应用于多光子成像、高分辨率时域太赫兹光谱、超连续谱产生等多个重要领域。但是,半导体增益介质纳秒量级的载流子寿命,极大地限制了锁模VECSEL重复频率的降低和峰值功率的提高。使用特殊设计的可饱和布拉格反射镜(SBR)作为可饱和吸收体,其中等适度的饱和通量可以有效地平衡谐振腔内的循环功率和多脉冲的产生,从而在较低的重复频率下保持足够高的平均输出功率,显著提高脉冲的峰值功率。SBR被动锁模VECSEL的脉冲重复频率被降低到67 MHz,激光器在基波、二次谐波和四次谐波锁模状态下的脉冲峰值功率分别为2.33、3.00、1.23 kW,被动锁模VECSEL在低于100 MHz的重复频率下获得了kW量级脉冲峰值功率。另外,结合实验结果,对SBR锁模VECSEL中多脉冲的产生及谐波锁模过程的演化进行了定性的分析讨论。Objective A vertical-external-cavity surface-emitting laser(VECSEL)offers unique advantages such as high power,good beam quality,and designable emitting wavelength.Additionally,the external-cavity structure allows for the convenient insertion of other optical components,thus enabling the VECSEL to operate in mode-locking,single-frequency running,or wavelength-tuning mode.These characteristics render the VESCEL a desirable candidate for various applications not realizable by conventional lasers(e.g.,solid-state lasers,gas lasers,fiber lasers,or laser diodes).In particular,the peak power pulses generated by a mode-locked VECSEL can be used in diverse fields such as multiphoton imaging,high-resolution time-domain terahertz spectroscopy,and supercontinuum generation.However,obtaining high peak-power pulses from a mode-locked VECSEL is not trivial.To increase the peak power of mode-locked pulses,one can increase the average output power of the laser,reduce the pulse time width,or reduce the pulse repetition rate.However,these three methods are mutually restrictive;thus,the pulse peak power in a mode-locked VECSEL can only be improved to a certain extent.In particular,the carrier lifetime of the semiconductor gain media used in a VECSEL is short,i.e.,in the nanosecond level,which significantly limits the further reduction of the repetition rate of mode-locked laser pulses.Consequently,the increase in the peak power of pulses generated from the mode-locked VECSEL is restricted considerably.Methods In this study,a custom-designed saturable Bragg reflector(SBR)was used as a saturable absorber,where a moderate saturation fluence can effectively balance between the cycling power and multi-pulse generation in the resonant cavity,thereby maintaining a sufficiently high average output power at low repetition rates and significantly improving the peak power of the modelocked laser pulses.The epitaxial structure of the gain chip used in the experiment(Fig.1)is a reverse-order structure of the active region,followed by a distribu

关 键 词：垂直外腔面发射激光器 被动锁模 重复频率 峰值功率 

分 类 号：TN245[电子电信—物理电子学]