基于光纤随机激光的1.7μm波段高功率涡旋光束产生  

1.7μm High-Power Vortex Beam Generation Based on Random Fiber Lasers

作　　者：于观玉 张春香 黄政 刘锐[3] 马瑞 白志勇 范滇元[1] 刘军[1] Yu Guanyu;Zhang Chunxiang;Huang Zheng;Liu Rui;Ma Rui;Bai Zhiyong;Fan Dianyuan;Liu Jun(International Collaborative Laboratory of 2D Materials for Optoelectronics Science and Technology of Ministry of Education,Shenzhen University Institute of Microscale Optoelectronics,Shenzhen 518060,Guangdong,China;College of Engineering Physics,Shenzhen Technology University,Shenzhen 518118,Guangdong,China;Guangdong and Hong Kong Joint Research Centre for Optical Fibre Sensors,College of Physics and Optoelectronic Engineering,Shenzhen University,Shenzhen 518060,Guangdong,China)

机构地区：[1]深圳大学微纳光电子学研究院二维材料光电科技国际合作联合实验室,广东深圳518060 [2]深圳技术大学工程物理学院,广东深圳518118 [3]深圳大学物理与光电工程学院光纤传感技术粤港联合研究中心,广东深圳518060

出　　处：《光学学报》2023年第22期222-229,共8页Acta Optica Sinica

基　　金：广东省基础与应用基础研究基金(2022A1515010326,2021A1515011532,2020A1515110471,2020A1515111143);深圳市科创委优青项目(RCYX20210609103157071);深圳市科创委重点项目(JCYJ20220818100019040);深圳技术大学新引进高端人才财政补助科研启动项(GDRC202138)。

摘　　要：1.7μm激光处于眼安全波段并位于许多重要气体分子的指纹吸收峰,在生物医疗、气体传感等领域具有重要应用价值。而涡旋光束作为一种新兴的结构光场,其具有环形光强分布和螺旋相位波前,并携带轨道角动量,在光通信、微粒操控等领域应用广泛。因此发展1.7μm高能涡旋激光器具有重要的研究价值和应用前景。但传统稀土离子掺杂光纤或晶体的发射谱,或难以覆盖该波段,或在该波段激光增益较小,且涡旋光产生主要基于空间光结构,导致1.7μm波段涡旋光激光系统复杂、集成度低,难以实现高功率输出。本文利用螺旋长周期光纤光栅作为涡旋模式转换器,在基于受激拉曼散射效应的1.7μm波段光纤随机激光半开放腔中实现了全光纤结构的高功率涡旋激光输出,最大输出功率为2.09 W,中心波长为1690 nm。得益于涡旋光纤随机激光器的全光纤结构,该装置具有良好的时域稳定性,短时时域波动低至2.8%。该研究结果不仅为实现兼具高功率输出和良好时域稳定性的紧凑型1.7μm波段涡旋激光器提供有效方案,还能进一步拓展其在激光医疗、气体检测、光镊和生物成像等领域的应用。Objective Since 1.7μm lasers are located in the eye-safe wavelength band and also within the fingerprint absorption peaks of many important gas molecules,they have potentially important applications in biomedical,gas sensing,and other fields.Meanwhile,as a novel structured light field,vortex beams can have unique features like annular light intensity distribution,helical phase wavefront,and orbital angular momentum.Therefore,developing high-performance 1.7μm vortex lasers and investigating involved technologies can further expand the application fields of the lasers,providing scientific significance and application prospects.It is generally difficult for traditional rare-earth-ion doped fibers and crystals to cover the 1.7μm emission band,or they can only have very weak laser gain in this wavelength band.Additionally,the vortex beam generation usually relies on a free-space lasing structure.These factors ultimately result in a complex vortex lasing configuration operating in the 1.7μm band with extremely poor integration and low output power.Thus,we employ a helical long-period fiber grating as a vortex mode converter,and propose a high-power all-fiber vortex laser based on a 1.7μm random fiber laser(RFL)with half-opened cavity,producing a maximum output power of 2.09 W at 1690 nm.Benefiting from the all-fiber structure of the vortex RFL,the laser output shows excellent temporal stability with a short-term temporal fluctuation as low as 2.8%.The results can not only provide a feasible approach to achieve a compact 1.7μm high-power vortex laser with excellent temporal stability,but also further expand its applications in laser medicine,gas detection,optical tweezers,biological imaging,and other fields.Methods First,a 1.7μm high-power RFL is constructed based on the stimulated Raman scattering effect.Then,a helical long-period fiber grating is adopted as a vortex mode converter with the vortex mode conversion efficiency of about 97%corresponding to 16 dB,which can convert the 1.7μm random lasing into a firs

关 键 词：1.7μm波段 涡旋光束 光纤随机激光器 螺旋长周期光纤光栅 涡旋光纤随机激光器 

分 类 号：TN248[电子电信—物理电子学]