高重复频率192~300 nm连续可调谐超短脉冲激光器  

High⁃Repetition⁃Rate Continuously Tunable Ultra⁃Short Pulse Laser Across Range from 192 nm to 300 nm

作　　者：刘华刚[1] 阮开明[1] 李锦辉[1] 史斐[1] 黄见洪[1] 林文雄[1] Liu Huagang;Ruan Kaiming;Li Jinhui;Shi Fei;Huang Jianhong;Lin Wenxiong(Key Laboratory of Optoelectronic Materials Chemistry and Physics,Fujian Institute of Research on the Structure of Matter,Chinese Academy of Sciences,Fuzhou 350002,Fujian,China)

机构地区：[1]中国科学院福建物质结构研究所中国科学院光电材料化学与物理重点实验室,福建福州350002

出　　处：《中国激光》2024年第7期180-186,共7页Chinese Journal of Lasers

基　　金：国家自然科学基金(62275247,11327804)。

摘　　要：报道了一种高重复频率、宽波段连续可调谐的紫外/深紫外超短脉冲激光器,调谐范围为192~300 nm。该激光器采用可调谐的钛宝石锁模激光器作为基频光源,通过优化设计多级倍频/和频组合与非线性晶体角度,分三个波段进行频率上转换,分别产生了192~210 nm、210~250 nm、250~300 nm的深紫外/紫外激光,最终合成一路覆盖192~300 nm的连续可调谐超短脉冲激光,同时还获得了调谐范围为375~500 nm的紫外/可见光波段的激光输出。光束切换、晶体角度调节、群速补偿、光束指向稳定等过程的电控设计,使得激光器在整个调谐过程中可由程序控制,无需复杂的人工调节,具备了单台激光器的可操控性和实用性。Objective Ultraviolet and deep ultraviolet ultrafast lasers have important applications in the development of ultraviolet semiconductor devices,ultrafast spectroscopy,and extreme ultraviolet laser generation owing to their advantages,such as ultrahigh temporal and spatial resolution.Continuous wavelength tuning in the ultraviolet and deep-ultraviolet ranges can expand the applicability of such lasers to satisfy the application requirements of different materials and research fields.However,many technical challenges remain for continuously tunable ultrashort pulse lasers that cover ultraviolet and deep-ultraviolet wavelengths below 200 nm to 300 nm.This study reports the development of a high-repetition-rate continuously tunable ultraviolet/deep ultraviolet ultrashort pulse laser with a tuning range covering the 192‒300 nm wavelength band.Methods A commercial tunable Ti∶sapphire mode-locked laser with a continuously tunable output wavelength in the range of 690‒1040 nm,a pulse width of 120 fs,and a repetition rate of 80 MHz is used as the fundamental laser.The BBSAG crystal,an improved BBO crystal,is used as the frequency conversion medium.In theory,a fundamental laser wavelength can be converted into a wide range of ultraviolet/deep-ultraviolet wavelengths of 190‒300 nm through cascaded frequency doubling and sum-frequency mixing.However,tuning the crystal angle over a wide range can significantly decrease the frequency-doubling efficiency.In addition,owing to the limitations of the phase-matching conditions of BBSAG crystals,laser wavelengths below 205 nm can be generated only through multistage sum-frequency mixing.Based on these factors,the laser is divided into three wavelength bands to generate ultrashort pulse lasers covering a wide range of 192‒300 nm by optimizing the design of the multilevel frequency-doubling/sumfrequency mixing and nonlinear crystal angle.Results and Discussions The laser system consists of three laser modules.In Module 1,a laser in the range of 210‒250 nm is generated by d

关 键 词：激光器 非线性激光变频 深紫外激光 超快激光 可调谐 

分 类 号：O437.1[机械工程—光学工程]