高峰值功率Nd:YLF/BaWO_(4)正交偏振双波长拉曼激光器  

High-peak-power orthogonally-polarized dual-wavelength Nd:YLF/BaWO_(4) Raman laser

作　　者：樊莉 向柯赟 沈君 朱骏 Fan Li;Xiang Ke-Yun;Shen Jun;Zhu Jun(Institute of Applied Photonic Technology,College of Physics Science and Technology,Yangzhou University,Yangzhou 225002,China)

机构地区：[1]扬州大学物理科学与技术学院,应用光子技术研究所,扬州225002

出　　处：《物理学报》2022年第9期131-138,共8页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:11774301)资助的课题。

摘　　要：正交偏振双波长激光在精密测量、太赫兹产生、差分雷达、光谱分析等领域有着重要的应用前景.Nd:YLF晶体具有两个发射截面相近的正交偏振发射峰,加上优异的储能性能和热性能,是适合产生正交偏振双波长激光的优良增益介质.本文采用低掺杂浓度的Nd:YLF晶体作为激光增益介质产生1047 nm和1053 nm的正交偏振双波长基频光,通过适当增大抽运光斑降低Nd:YLF晶体热裂的风险,利用Nd:YLF/BaWO_(4)晶体的腔内拉曼频移,实现了高峰值功率的1159.9 nm和1167.1 nm正交偏振双波长脉冲拉曼激光输出.在40 W的总入射抽运功率和5 kHz的脉冲重复频率下,获得平均输出功率为2.67 W的双波长拉曼激光输出,相应的光光转换效率为6.7%.1159.9 nm和1167.1 nm拉曼激光输出功率分别为1.31 W和1.36 W,最窄脉冲宽度分别为1.50 ns和1.53 ns,对应的峰值功率分别高达174.7 kW和177.8 kW.结果表明,降低掺杂浓度和增大抽运光斑可有效解决Nd:YLF晶体在高抽运功率下发生热裂的问题,Nd:YLF/BaWO4是实现正交偏振双波长拉曼激光输出的一种较有前途的晶体组合.Orthogonally-polarized dual-wavelength laser has significant practical applications in various fields,such as precision metrology,terahertz radiation generation,differential radar,spectral analysis.The Nd:YLF crystal has two orthogonally-polarized emission peaks with comparable emission cross sections,high-energy storage capability and relatively weak thermal lens effect.Owing to these properties,it has been recognized as a suitable gain medium for generating orthogonally-polarized dual-wavelength laser.In this paper,the Nd:YLF crystal with low doping concentration is employed as a laser gain medium to produce 1047 nm and 1053 nm dual-wavelength fundamental lasers with orthogonal polarizations,and the risk of thermal cracking of Nd:YLF crystal is reduced by appropriately increasing the pump spots.Using the intracavity Raman frequency shift in Nd:YLF/BaWO_(4)crystal,orthogonally-polarized dual-wavelength Raman lasers at 1159.9 nm and 1167.1 nm are achieved to have high peak power.Under the total incident pump power of 40 W and a pulse repetition rate of 5 kHz,the maximum dual-wavelength Raman output power is obtained to be 2.67 W.The corresponding total optical conversion efficiency is 6.7%.For 1159.9 nm and 1167.1 nm Raman laser,their maximum average output power values are 1.31 W and 1.36 W,respectively.Their narrowest pulse widths are 1.50 ns and 1.53 ns,and the corresponding peak power values are as high as 174.7 kW and 177.8 kW,respectively.The results show that the problem of thermal cracking of Nd:YLF crystal at high pump power can be solved by reducing the doping concentration and increasing the pump spot.The Nd:YLF/Nd:YLF/BaWO_(4) is a promising crystal combination for realizing orthogonally-polarized dual-wavelength Raman laser.

关 键 词：双波长拉曼激光 正交偏振 主动调Q Nd:YLF晶体 

分 类 号：TN248[电子电信—物理电子学]