高转换效率腔内倍频外腔面发射蓝光激光器
Intracavity frequency-doubled external-cavity surface-emitting blue laser with high conversion efficiency
摘要
Abstract
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 and 490 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 at 491 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.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Key words
intracavity frequency-doubled/external-cavity surface-emitting blue laser/type-I phase matching/compensation of walk off angle引用本文复制引用
伍亚东,朱仁江,晏日,彭雪芳,王涛,蒋丽丹,佟存柱,宋晏蓉,张鹏..高转换效率腔内倍频外腔面发射蓝光激光器[J].物理学报,2024,73(1):94-100,7.基金项目
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)和重庆师范大学基金项目(批准号:23XLB003)资助的课题.Project supported by the Cooperation Project between Chongqing Local Universities and Institutions of Chinese Academy of Sciences,Chongqing Municipal Education Commission(Grant No.HZ2021007),the Science and Technology Research Program of Chongqing Municipal Education Commission,China(Grant No.KJZD-M201900502),the Science and Technology Research Program of Chongqing Municipal Education Commission,China(Grant No.KJQN202200557),the National Natural Science Foundation of China(Grant Nos.61975003,61790584,62025506),and the Chongqing Normal University Foundation,China(Grant No.23 XLB003). （批准号:HZ2021007）
