同带泵浦的Tm:CYA调Q锁模激光器  

Tm:CYA Q-switched mode-locked laser realized by tandem-pumping

作　　者：孙堂正 李云飞 谭晶荣[1,2] 杜晓娟 丁嘉宇 任舒婷 许浩 王翀[1,2] 杨金芳 张明霞[1,2] 朱永乐 董忠 令维军 SUN Tang-zheng;LI Yun-fei;TAN Jing-rong;DU Xiao-juan;DING Jia-yu;REN Shu-ting;XU Hao;WANG Chong;YANG Jin-fang;ZHANG Ming-xia;ZHU Yong-le;DONG Zhong;LING Wei-jun(Gansu All-Solid State Laser Engineering Research Center,Tianshui 741001,China;Integrated Circuit Engineering Research Center of the Ministry of Education,Tianshui 741001,China)

机构地区：[1]甘肃省全固态激光工程研究中心,甘肃天水741001 [2]集成电路封装与测试教育部工程研究中心,甘肃天水741001

出　　处：《中国光学（中英文）》2024年第4期764-770,共7页Chinese Optics

基　　金：国家自然科学基金(No.62165012);甘肃省重点研发计划(No.21YFIGE300);甘肃省高等学校产业支撑引导项目(No.2020C-23);甘肃省教育厅:教育揭榜挂帅项目(No.2021jyjbgs-06);甘肃省高等学校创新基金项目(No.2021B-190);秦州区科技计划(No.2021-SHFZG-1442);2023年甘肃省高校青年博士支持项目(No.2023QB-013);天水师范学院2022年科研创新平台建设专项(No.PTJ2022-06);天水师范学院研究生创新引导项目(No.TYCX2235);甘肃省优秀研究生创新之星项目(No.2022CXZX-796,No.2023CXZX-792)。

摘　　要：以半导体可饱和吸收镜SESAM作为锁模启动元件,利用同带泵浦技术首次在Tm:CaYALO_(4)(Tm:CYA)激光器实现了被动调Q锁模运转。光路采用X型四镜腔结构,泵浦源采用Er:Y_(3)Al_(5)O_(12)(Er:YAG)固体激光器,其中心波长为1650 nm。分别采用0.5%、1.5%、3%和5%透过率的输出耦合镜,对激光器连续光输出和锁模输出特性进行研究。结果表明:当采用5%透过率的输出耦合镜时,激光器的输出特性最好;当激光器在连续光运转情况下,得到了894 mW的最高功率和16%的最大斜效率输出;将连续光功率优化至最高,在光路中加入SESAM锁模元件后,当吸收泵浦功率大于1.86 W时,激光运转进入不稳定的调Q状态;当吸收泵浦功率提高到5.7 W时,实现了稳定的被动调Q锁模运转;吸收泵浦功率达到6.99 W时,采用5%透过率的输出耦合镜,获得了最高输出功率为399 mW的锁模脉冲激光;此时调Q包络下重复频率为98.11 MHz,脉冲宽度为619.4 ps,对应的最大单脉冲能量为4.07 nJ,调Q包络中锁模脉冲调制深度接近100%。实验结果证明,同带泵浦技术可以用于激光器以产生调Q锁模脉冲,为超短脉冲激光的产生提供了一种新的泵浦方式。Passively Q-switched mode-locked operation was realized for the first time by inserting a semicon-ductor saturable absorption mirror(SESAM)as a mode-locking element into a Tm:CaYALO_(4)(Tm:CYA)laser using tandem-pumping technology.The laser cavity adopted an X-type four-mirror cavity structure,and the pumping source was an Er:Y_(3)Al_(5)O_(12)(Er:YAG)solid-state laser with a central wavelength of 1650 nm.Output coupling mirrors with transmittances of 0.5%,1.5%,3%,and 5%were used to study the laser’s con-tinuous wave(CW)output and mode-locking output characteristics.The experimental results show that the laser has the best output characteristics when an output coupling mirror with a transmittance of 5%is used.The maximum power of 894 mW and the maximum slope efficiency of 16%were obtained when the laser operated in the CW regime.After the CW power was optimized to the highest,the mode-locked element SESAM was added to the optical path.When the absorbed pump power became greater than 1.86 W,the laser operation entered an unstable Q-switched state;when the absorbed pump power increased to 5.7 W,a stable passively Q-switched mode-locked operation was achieved;when the absorbed pump power reached 6.99 W,a mode-locked pulse laser with a maximum output power of 399 mW was obtained by using the out-put coupling mirror with transmittance of 5%.At that time,the repetition frequency under the Q-switched en-velope was 98.11 MHz,the pulse width was 619.4 ps,and the corresponding maximum single pulse energy was 4.07 nJ.The mode-locked pulse modulation depth in a Q-switched envelope was observed to be close to 100%.The above results show that tandem-pumping technology can be used in lasers to generate Q-switched mode-locked pulses,which provides a new pumping method for generating ultrashort pulse lasers.

关 键 词：Tm:CYA激光器 同带泵浦 半导体可饱和吸收镜(SESAM) 调Q锁模 

分 类 号：TN248.1[电子电信—物理电子学]