绿光泵浦的克尔透镜锁模翠绿宝石激光器  

Green⁃Pumped Kerr⁃Lens Mode⁃Locked Alexandrite Laser

作　　者：杨云霄 于洋[2] 田文龙[1] 朱江峰[1] 魏志义[3] Yang Yunxiao;Yu Yang;Tian Wenlong;Zhu Jiangfeng;Wei Zhiyi(School of Optoelectronic Engineering,Xidian University,Xi’an 710071,Shaanxi,China;Academy of Advanced Interdisciplinary Research,Xidian University,Xi’an 710071,Shaanxi,China;Beijing National Laboratory for Condensed Matter Physics,Institute of Physics,Chinese Academy of Sciences,Beijing 100190,China;China Jiangnan Space Industry Company Group,Guiyang 550009,Guizhou,China)

机构地区：[1]西安电子科技大学光电工程学院,陕西西安710071 [2]西安电子科技大学前沿交叉研究院,陕西西安710071 [3]中国科学院物理研究所北京凝聚态物理国家研究中心,北京100190 [4]航天江南集团有限公司,贵州贵阳550009

出　　处：《中国激光》2024年第2期54-59,共6页Chinese Journal of Lasers

基　　金：国家自然科学基金(11774277,62105253);科技部国家重点研发计划(2017YFB0405202);中央高校基本科研业务费(ZD2006,XJS222206)。

摘　　要：翠绿宝石激光器在医疗美容等领域发挥着重要的作用,其通常采用红光二极管(LD)激光器作为泵浦源,可以获得较高的转化效率,但红光LD激光器的光束质量较差,不适合直接作为克尔透镜锁模激光器的泵浦源,商用的绿光激光器以其优异的光束质量成为了克尔透镜锁模翠绿宝石激光器的首选泵浦源。报道了一种绿光泵浦的克尔透镜锁模翠绿宝石激光器。实验采用商用532 nm全固态绿光激光器作为翠绿宝石激光器的泵浦源,当泵浦光功率为10 W时,实现了稳定的锁模脉冲输出,重复频率为92 MHz,平均功率为369 mW,脉冲宽度为86 fs,中心波长为749 nm,光谱半峰全宽为6.3 nm。Objective A green-pumped Kerr lens mode-locked alexandrite laser is reported.A commercial 532-nm solid-state laser is used as the pump source for the alexandrite laser.Utilizing the pump power of 10 W,stable mode-locked operation at a repetition rate of 92 MHz,with an average power of 369 mW,is obtained.In this case,the pulse width is 86 fs,center wavelength is 749 nm,and full width at half maximum is 6.3 nm.Methods The alexandrite crystal with a length of 3 mm and doping atomic fraction of 0.22%was selected as the gain medium in the experiment.Given that the pump laser was linearly polarized,the crystal was cut at the Brewster angle and clamped onto a copper heat sink that could pass through the circulating water.To test the conversion efficiency of continuous waves,we measured the continuous-wave output power using coupling output mirrors(OCs)with different transmissivities.Then,we conducted an experimental study on Kerr lens mode locking using an OC with 2%transmissivity.The mode-locking operation was realized by adjusting concave mirror M2 to find a suitable mode-locked position and by appropriately changing the insertion of prism P2.Results and Discussions When we explore the characteristics of the continuous wave,we obtain the continuous-wave output power curves for different pump powers,as shown in Fig.2(a).Among them,the highest continuous-wave output power of 1.33 W is realized by an OC with 2%transmissivity,and the output power threshold is 0.37 W,corresponding to a slope efficiency of 14.3%.The highest continuous-wave output powers of 918 mW and 1.03 W are obtained using OCs with 1%and 3%transmissivities,respectively.Furthermore,the output power thresholds are 0.42 W and 2.38 W,corresponding to slope efficiencies of 9.7%and 14.4%,respectively.Additionally,we use an output coupling mirror with 2%transmissivity to examine alexandrite laser Kerr lens mode-locking.Utilizing the pump power of 10 W,the stable mode-locked operation at a repetition rate of 92 MHz,with an average power of 369 mW,is obtained.The

关 键 词：激光器 全固态激光器 绿光泵浦 克尔透镜锁模 翠绿宝石 

分 类 号：TN248.1[电子电信—物理电子学]