摘要
高功率高光束质量的蓝色激光在激光显示与照明、水下通信和成像、有色金属加工等许多领域具有广泛应用前景.本文利用增益芯片底部的高反镜分布布拉格反射镜、折叠镜以及后端反射镜构成V型谐振腔,通过腔内插入非线性晶体LBO,获得了高转换效率的高功率、高光束质量蓝光输出.实验研究了非线性晶体的长度、基频激光的线宽、倍频走离角的补偿等不同因素对外腔面发射激光器腔内倍频蓝光输出功率的影响.在LBO的Ⅰ类相位匹配条件下,当晶体长度为5 mm,所用双折射滤波片厚度为1 mm时,获得超过6 W的491 nm波长蓝光输出,x和y方向的光束质量M2因子均为1.08,倍频转换效率为63%.
Blue laser with high power and high beam quality has many applications such as in laser display,underwater communication and imaging,and non-ferrous metal processing.Optically pumped external-cavity surface-emitting laser combines the advantages of both surface-emitting semiconductor lasers and solid-state disk lasers,and can produce high output power and good beam quality simultaneously.Its high intracavity circulating power is more conducive to intracavity frequency doubling,achieving high-power and high beam quality blue light through fundamental laser in the near-infrared waveband.This paper reports an efficient intracavity frequency doubled 490 nm high power blue light by using a 980 nm fundamental laser in an external-cavity surface-emitting laser.The V-type resonant cavity is formed by the high reflectivity distributed Bragg reflector(DBR)at the bottom of gain chip,a folded flat concave mirror(high reflectivity coated for 980 nm and anti-reflectivity coated for 490 nm),and a flat concave end mirror(high reflectivity coated for 980 nm and490 nm).By inserting a nonlinear crystal LBO into the cavity at the beam waist formed by the folded mirror and end mirror,and employing a birefringent filter(BRF)to polarize the fundamental laser and narrow the linewidth of the laser,a high power and high beam quality blue laser with high conversion efficiency is obtained.The effects of different factors including the length of nonlinear crystal,the linewidth of fundamental laser,and the compensation of walk off angle on the output power of the blue laser are studied experimentally.The length of the nonlinear crystal is optimized based on the size of the fundamental laser beam waist at the position of the crystal in the resonant cavity.Under the type-I phase matching condition of LBO,over 6 W output power at491 nm wavelength is obtained when the crystal length is 5 mm and the BRF thickness is 1 mm.The beam quality M2 factor in the x direction and the y direction are both 1.08,and the conversion efficiency of frequency doubling is 63%.The experimental results also show that symmetrically placed nonlinear crystals can compensate for the walk-off angle during frequency doubling to a certain extent,thereby clearly improving the conversion efficiency of the frequency doubled blue laser.
作者
伍亚东
朱仁江
晏日
彭雪芳
王涛
蒋丽丹
佟存柱
宋晏蓉
张鹏
Wu Ya-Dong;Zhu Ren-Jiang;Yan Ri;Peng Xue-Fang;Wang Tao;Jiang Li-Dan;Tong Cun-Zhu;Song Yan-Rong;Zhang Peng(College of Physics and Electronic Engineering,Chongqing Normal University,Chongqing 401331,China;Changchun Institute of Optics,Fine Mechanics and Physics,Chinese Academy of Sciences,Changchun 130033,China;Faculty of Sciences,Beijing University of Technology,Beijing 100124,China;National Center for Applied Mathematics in Chongqing,Chongqing Normal University,Chongqing 401331,China)
出处
《物理学报》
SCIE
EI
CAS
CSCD
北大核心
2024年第1期174-180,共7页
Acta Physica Sinica
基金
在渝本科高校与中国科学院所属院所合作项目(批准号:HZ2021007)
重庆市教委科技计划重大项目(批准号:KJZD-M201900502)
重庆市教委科技计划(批准号:KJQN202200557)
国家自然科学基金(批准号:61975003,61790584,62025506)
重庆师范大学基金项目(批准号:23XLB003)资助的课题。
关键词
腔内倍频
外腔面发射蓝光激光器
Ⅰ类相位匹配
走离角补偿
intracavity frequency-doubled
external-cavity surface-emitting blue laser
type-I phase matching
compensation of walk off angle
