光纤气体激光光源研究进展及展望(Ⅱ):基于粒子数反转  

Research Progress and Prospect of Fiber Gas Laser Sources(Ⅱ):Based on Population Inversion

作　　者：王泽锋 周智越 崔宇龙 黄威 李智贤 李昊[1] Wang Zefeng;Zhou Zhiyue;Cui Yulong;Huang Wei;Li Zhixian;Li Hao(College of Advanced Interdisciplinary Studies,National University of Defense Technology,Changsha Hunan 410073 China;State Key Laboratory of Pulsed Power Laser Technology,Changsha Hunan 410073 China;Hunan Provincial Key Laboratory of High Energy Laser Technology,Changsha Hunan 410073 China)

机构地区：[1]国防科技大学前沿交叉学科学院,湖南长沙410073 [2]脉冲功率激光技术国家重点实验室,湖南长沙410073 [3]高能激光技术湖南省重点实验室,湖南长沙410073

出　　处：《中国激光》2021年第4期152-167,共16页Chinese Journal of Lasers

基　　金：国家自然科学基金面上项目(11974427,12004431);湖南省自然科学基金杰出青年科学基金项目(2019JJ20023);脉冲功率激光国家重点实验室主任基金项目(SKL-2020-ZR05)。

摘　　要：粒子数反转和受激拉曼散射是实现光纤气体激光器输出的最常见的两种基本原理。与光纤气体拉曼激光光源不同,基于粒子数反转原理的光纤气体激光器是通过气体分子振转能级的本征吸收跃迁实现激光输出。由于绝大多数气体分子的振转能级对应的激射跃迁谱线都在中红外波段,这种激光器的输出波长基本都在中红外波段。简要分析了基于粒子数反转原理的光纤气体激光器在产生中红外波段激光方面的优势,重点回顾了其发展历史与研究现状,并对下一步的发展趋势进行了展望。Significance A fiber gas laser(FGL)based on gas filled hollow-core fibers(HCFs)is a laser source that combines the advantages of traditional gas and fiber lasers.According to the operating mechanism,FGLs can be divided into two categories:one is based on the stimulated Raman scattering(SRS)of gas molecules,and the other is based on population inversion realized by intrinsic absorption of gas molecules between the vibrational-rotational energy levels.The threshold power for population inversion is much lower than that for the SRS effect,making it easier to realize continuous-wave(CW)laser emission.The laser wavelengths corresponding to the vibrational-rotational energy level transition of most gas molecules are in the mid-infrared waveband;thus,the FGLs based on population inversion provide a novel method for the mid-infrared fiber lasers,which have wide applicability in military,biomedicine,and atmospheric communication fields.In HCFs,most of the mode energy is concentrated in the hollow-core.The laser mode edge overlaps with a small amount of glass material in the cladding.As the field intensity in the glass material is at least one order of magnitude smaller than the peak field intensity in the core region,the theoretical damage threshold of HCFs is much higher than that of solid-core fibers,making HCFs ideal to operate at much higher power level.Meanwhile,the hollow-core structure can be filled with various gain gas media to achieve plenty of laser wavelengths,especially beyond 4μm,which is very difficult for traditional rare-earth-doped fiber lasers.Because of the intrinsic properties of gas molecular energy levels,laser output with narrow linewidth(several-hundred MHz)can also be obtained without additional linewidth control technology for FGLs,which has great advantages in maintaining laser linewidth at high power compared with lasers using solid-core fibers.Hence,FGLs provide a universal solution for the technical bottlenecks encountered by traditional mid-infrared fiber lasers in power enhancement and wa

关 键 词：激光器 红外和远红外激光器 分子气体激光器 空芯光纤 

分 类 号：TN24[电子电信—物理电子学]