全固态瓦级388 nm紫外连续激光器  

All-solid-state watt-level 388 nm continuous-wave ultraviolet laser

作　　者：钱龙龙 沈咏 刘曲[1] 邹宏新[1] QIAN Longlong;SHEN Yong;LIU Qu;ZOU Hongxin(College of Science,National University of Defense Technology,Changsha 410073,China)

机构地区：[1]国防科技大学理学院,湖南长沙410073

出　　处：《量子电子学报》2023年第3期392-399,共8页Chinese Journal of Quantum Electronics

基　　金：国家自然科学基金面上项目(62275268);湖南省自然科学基金重点项目(2019JJ50743)。

摘　　要：采用自行研制的776.9 nm半导体激光器作为种子源,经过锥形半导体放大器并整形后得到2.3 W的基频光,再利用Ⅰ类相位匹配的三硼酸锂晶体和蝶形倍频腔产生了388.4 nm紫外连续激光。分析了锥形放大器中热透镜效应对光束质量的影响,并通过透镜、柱面镜、棱镜对光束进行整形,提高了倍频腔的输入耦合效率。进一步通过优化倍频腔的束腰尺寸和腔参数,提高了紫外激光二次谐波的转换效率。最终2.3 W的基频光产生940 mW的紫外倍频光输出,倍频效率达到41%。Using a homemade 776.9 nm semiconductor laser as seeder,a 2.3 W fundamental frequency output is obtained through amplification of a tapered amplifier(TA)and shaping.Then,a 388.4 nm continuous-wave laser is generated by the second harmonic generation(SHG)of a Class I phase matched lithium borate(LBO)crystal with an external bow-tie cavity.It is shown that the severely thermal effect of TA can change the waist position of the generated laser beam and limit the conversion efficiency of the second harmonic generator.Therefore,the thermal effect of TA is analyzed,and a laser beam shaping scheme consisted of cylindrical lens,prism pair and lens is proposed to compensate for the thermal effect.Furthermore,by optimizing the beam waist size and cavity parameters of the cavity,the conversion efficiency of the second harmonic is improved.Finally,the basic frequency input of 2.3 W can generate a ultraviolet laser output of 940 mW,with SHG efficiency of 41%.

关 键 词：非线性光学 紫外连续激光 二次谐波 热透镜效应 三硼酸锂晶体 

分 类 号：O437.1[机械工程—光学工程]