应用于1064 nm倍频实验的啁啾周期极化铌酸锂晶体的结构设计与角度鲁棒性测试  

Design and angular robustness test of chirped periodically poled lithium niobate crystal for 1064 nm second-harmonic generation experiment

作　　者：刘励强 苏伟伦 刘峻铭 邹娱 洪丽红 李志远 Liu Li-Qiang;Su Wei-Lun;Liu Jun-Ming;Zou Yu;Hong Li-Hong;Li Zhi-Yuan(School of Physics and Optoelectronics,South China University of Technology,Guangzhou 510641,China;Guangdong Jingchuang Optical Machinery Co.,LTD,Guangzhou 510510,China;State Key Laboratory of High Field Laser Physics,Shanghai Institute of Optics and Fine Mechanics,Chinese Academy of Sciences,Shanghai 201800,China)

机构地区：[1]华南理工大学物理与光电学院,广州510641 [2]广东晶创光学机械有限公司,广州510510 [3]中国科学院上海光学精密机械研究所,强场激光物理国家重点实验室,上海201800

出　　处：《物理学报》2024年第17期185-193,共9页Acta Physica Sinica

摘　　要：通过倍频技术产生的532 nm固体激光器是目前应用最广泛的激光器之一,其最常用的倍频晶体三硼酸锂(LBO)在角度鲁棒性与倍频效率上仍有不足.为获得具有较好的角度鲁棒性的倍频晶体,实现激光器结构复杂度的降低与稳定性的提升,本文从角度鲁棒性的理论分析出发,对啁啾周期极化铌酸锂(CPPLN)晶体的结构进行设计,并对其进行理论仿真与实验测试.模拟仿真的结果表明,该设计结构的CPPLN晶体具有良好的角度鲁棒性,在-3°至+3°的范围内倍频效率一直维持在最高倍频效率的60%以上.倍频实验的结果显示可以达到LBO晶体的11倍以上.同时CPPLN晶体的倍频光功率关于入射角度的半高宽可以达到6°以上,并且出射光斑为标准的高斯光斑,几乎不受入射角度的影响.研究表明,CPPLN晶体具有远高于LBO晶体的倍频效率,且角度鲁棒性优于LBO晶体的角度鲁棒性.A 532-nm solid-state laser,generated by second-harmonic generation(SHG)technology,has become one of the most extensively used lasers in various applications today.In the traditional scheme,the most prevalent SHG crystal of the 532-nm solid-state is lithium borate(LBO),and continues to exhibit insufficient angular robustness and SHG efficiency.In order to overcome these limitations and obtain SHG crystals with better angular robustness,this study starts with a comprehensive theoretical analysis of angular robustness.On this basis,the structure of a chirped periodically poled lithium niobate(CPPLN)crystal is designed by taking into account the desired properties for improving its performance,and then the theoretical simulations and experimental tests are implemented to validate the effectiveness of the designed crystal.The simulation results corroborate the superior angular robustness of the CPPLN crystal.In a range from-3°to+3°,the designed CPPLN crystal exhibits a maximum SHG efficiency of 0.80%and a minimum one of 0.51%,which indicates that the SHG efficiency of this crystal in this range can be maintained at 60%of the maximum efficiency.The experimental results show that the SHG efficiency can be more than 11 times that of LBO crystal.Moreover,the study indicates that the half width of the actual SHG efficiency near the incident angle of the designed CPPLN crystal can exceed 6°,demonstrating its excellent tolerance for changes in incident angle.Furthermore,the output spot of the SHG light generated by the designed CPPLN crystal exhibits a standard Gaussian profile,which remains virtually unaffected by the incident angle.In summary,the findings of this research highlight the CPPLN crystal as a promising alternative to LBO,with markedly higher SHG efficiency and better angular robustness.These superior characteristics make the CPPLN crystal a highly attractive candidate for a wide range of laser applications.

关 键 词：非线性光学 啁啾周期极化铌酸锂晶体 腔外倍频 角度鲁棒性 

分 类 号：TN248[电子电信—物理电子学] O734[理学—晶体学]