大模场一维高阶厄米-高斯激光束产生  

Generation of one-dimensional high-order Hermite-Gaussian laser beams with large mode volume

作　　者：周王哲 李雪鹏 杨晶[1,4] 杨天利 王小军 刘炳杰 王浩竹 杨俊波 彭钦军 Zhou Wang-Zhe;Li Xue-Peng;Yang Jing;Yang Tian-Li;Wang Xiao-Jun;Liu Bing-Jie;Wang Hao-Zhu;Yang Jun-Bo;Peng Qin-Jun(Key Laboratory of Solid State Laser,Technical Institute of Physics and Chemistry,Chinese Academy of Sciences,Beijing 100190,China;University of Chinese Academy of Sciences,Beijing 100049,China;College of Liberal Arts and Sciences,National University of Defense Technology,Changsha 410073,China;Institute of Optical Physics and Engineering Technology,Qilu Zhongke,Jinan 250000,China)

机构地区：[1]中国科学院理化技术研究所,中国科学院固体激光重点实验室,北京100190 [2]中国科学院大学,北京100049 [3]国防科技大学文理学院物理系,长沙410073 [4]齐鲁中科光物理与工程技术研究院,济南250000

出　　处：《物理学报》2023年第1期133-140,共8页Acta Physica Sinica

摘　　要：厄米-高斯光束在诸多前沿科学领域都有着重要的应用.不同于目前普遍采用的晶体端面离轴泵浦方式,本文提出了一种利用板条激光器产生厄米-高斯激光束的方法.采用半导体激光阵列大面正交泵浦板条激光介质,具有大模场特性.根据预先设计的谐振腔模场,在板条厚度和宽度方向分别采用尺寸可调的光阑限模.由于高阶模式对谐振腔腔镜不对准的灵敏度弱于低阶模式,可通过耦合输出镜倾斜量的控制,实现不同阶数模式腔内损耗的差异化调控,从而产生各阶次的高纯度厄米-高斯光束.利用Nd:YAG板条激光器,获得了0—9阶一维厄米-高斯光束,其光强分布与理论值的相关系数ρ高于0.95,光束质量因子M^(2)与理论值符合良好.最高阶HG09模式的输出功率为244 mW.在此基础上,进一步利用柱透镜对组成的像散模式转换器,实现了各阶厄米-高斯光束向对应拉盖尔-高斯光束的转换.结合板条放大器结构,基于本方案产生的厄米-高斯光束具备功率定标放大的前景.Hermite-Gaussian(HG)beams have many important applications in the optical frontier,and the limited output power of the high-purity HG beams is partly due to the small gain volume of the mode.The commonly used off-axis end-pumped scheme offers a narrow gain volume whose diameter is about a hundred microns.In this work,a new method of generating the HG beams based on a slab resonator that has a large mode volume is proposed and experimentally demonstrated.According to the optical resonator theory,the intra-cavity modes in thickness and width direction of the slab resonator are restricted by inserting two size-adjust able apertures,respectively.The one-dimensional HG beam generation is mainly guaranteed by the size of the aperture along the thickness direction of the slab,which matches the diameter of the fundamental mode.The different order one-dimensional HG beams are obtained by refined intra-cavity mode modulation.Since the higher-order modes are less sensitive to the misalignment of the cavity mirror than the lower-order modes,and the manipulation of the modes-loss at different orders is achieved by combining the tilt control of the coupled output mirror and the size control of intra-cavity apertures.By adjusting the optical gain and loss in the resonant cavity,the single mode wins the competition of laser modes.Therefore,high-purity one-dimensional HG beams with 0 to 9 orders(HG00to HG09)are generated.The pump module is comprised of a two-dimensional laser diode array which offers face-pumping to the large surface of the slab,therefore the width of the mode volume is extended to several millimeters.By further incorporating the 100mm-level long slab,the total gain volume is much larger than the counterpart in the off-axis pumping scheme.In this work,the output power of the highest order HG09mode increases up to 244 mW.Owing to the large gain volume and uniform gain distribution caused by the face-pumped slab,the purity of high order HG modes is quite good.The correlation coefficient p between the measured inten

关 键 词：厄米-高斯光束 板条激光器 大模场 倾斜量控制 功率定标放大 

分 类 号：TN248[电子电信—物理电子学]