光纤飞秒激光五倍频产生206 nm深紫外激光  

206 nm deep ultraviolet laser generated from fifth harmonic of femtosecond fiber laser

作　　者：石凉竹 张萌 储玉喜 刘博文 胡明列 Shi Liang-Zhu;Zhang Meng;Chu Yu-Xi;Liu Bo-Wen;Hu Ming-Lie(Key Laboratory of Opto-Electronic Information Technology(Ministry of Education),Ultrafast Laser Laboratory,College of Precision Instrument and Optoelectronics Engineering,Tianjin University,Tianjin 300072,China)

机构地区：[1]天津大学,精密仪器与光电子工程学院超快激光研究室,光电信息技术教育部重点实验室,天津300072

出　　处：《物理学报》2023年第22期194-199,共6页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:61805174,61535009,61827821,61377041,11527808,U1730115);广东省重点领域研发计划(批准号:2020B090922004);天津市自然科学基金(批准号:20JCQNJC01180)资助的课题。

摘　　要：深紫外飞秒激光兼具深紫外激光单光子能量高和飞秒激光峰值功率高的优势,这使得深紫外飞秒激光在半导体晶圆检测和角分辨光电子能谱等领域被广泛应用,但是色散导致的群速度失配使得深紫外飞秒激光的输出变得十分困难,本文基于掺镱光纤飞秒激光器,实现了一种基于延迟线的深紫外飞秒激光脉冲产生方案.通过优化延迟线精确补偿时间走离,基于掺镱飞秒光纤激光五倍频获得了重复频率为1 MHz、中心波长为206 nm的深紫外飞秒激光输出,其平均功率102 mW,从近红外到深紫外的转换效率为4.25%.Deep ultraviolet(DUV)femtosecond laser,which combines the advantages of high single-photon energy of DUV laser with high peak power of femtosecond laser,is widely used in scientific research,biomedicine,material processing and so on.However,in the process of generating DUV femtosecond laser based on nonlinear frequency conversion is encountered a problem that the group velocity mismatch caused by dispersion makes the temporal walk-off of the nonlinear frequency conversion larger than the pulse duration of the femtosecond laser,thus making the generation of the DUV femtosecond laser very difficult.In this work,based on a Ybdoped fiber femtosecond laser,the delay line is optimized to precisely compensate for the spatial and temporal walk-off,so DUV femtosecond laser possesses the following performances:the center wavelength is 206 nm,the repetition rate is 1 MHz,the maximum output power is 102 mW,the maximum conversion efficiency is 4.25%from near infrared to DUV,the root mean square(RMS)power stability is 0.88%within 3 h,and the peak-topeak power stability is 3.75%.The evolution of laser spectra and beam quality in the process of second harmonic generation(SHG),fourth harmonic generation(FHG)and sum-frequency generation(SFG)are also systematically studied.The experimental results provide a basis for generating DUV femtosecond laser from femtosecond fiber lasers.

关 键 词：非线性光学 飞秒光纤激光器 深紫外激光 时间走离 

分 类 号：TN248[电子电信—物理电子学]