基于声致光纤光栅输出1.1~1.5μm波段高功率随机涡旋光束  

1.1‒1.5μm Waveband High Power Random Vortex Beams Based on Acoustically-Induced Fiber Grating

作　　者：李阳[1] 姚天甫 范晨晨 郝修路 马小雅 许将明 张青松 曾祥龙[4] 周朴[1] Li Yang;Yao Tianfu;Fan Chenchen;Hao Xiulu;Ma Xiaoya;Xu Jiangming;Zhang Qingsong;Zeng Xianglong;Zhou Pu(College of Advanced Interdisciplinary Studies,National University of Defense Technology,Changsha 410073,Hunan,China;Nanhu Laser Laboratory,National University of Defense Technology,Changsha 410073,Hunan,China;Hunan Provincial Key Laboratory of High Energy Laser Technology,Changsha 410073,Hunan,China;Key Laboratory of Specialty Fiber Optics and Optical Access Networks,Joint International Research Laboratory of Specialty Fiber Optics and Advanced Communication,Shanghai University,Shanghai 200444,China)

机构地区：[1]国防科技大学前沿交叉学科学院,湖南长沙410073 [2]国防科技大学南湖之光实验室,湖南长沙410073 [3]高能激光技术湖南省重点实验室,湖南长沙410073 [4]上海大学特种光纤与光接入网重点实验室,特种光纤与先进通信国际合作联合实验室,上海200444

出　　处：《光学学报》2024年第10期414-421,共8页Acta Optica Sinica

基　　金：国家自然科学基金(12174445,62061136013)。

摘　　要：近年来,携带轨道角动量(OAM)的涡旋光束因具有重要研究价值和应用前景而备受关注。随着涡旋光束在传感、测量以及大容量光通信中的应用,输出带宽以及波长可调谐性成为关注的热点。突破稀土掺杂光纤发射波长限制和宽带模式转换的器件是实现特殊波段/宽带涡旋光输出的基础。为同时满足以上要求,本文采用基于分布式瑞利散射的随机拉曼光纤激光器结构,结合具备宽带模式转换能力的声致光纤光栅(AIFG),通过级联拉曼频移,实现了1133.9、1197.6、1260.5、1331.8、1414.5、1513.7 nm波长处拓扑荷数l=±1的涡旋光束输出,并通过自干涉实验进行验证。在1513.7 nm波长处功率为23.6 W,效率为31.1%。该研究不仅在全光纤中实现了紧凑的波长可调谐高功率涡旋光输出,验证了AIFG的超宽模式转换能力,也为其他波段涡旋光输出提供了参考方案,可进一步拓展涡旋光在多维光通信、光场与物质相互作用等领域的应用。Objective In recent years,vortex beams carrying orbital angular momentum(OAM)have caught much attention due to their research significance and application prospects.With the applications of vortex beams in sensing,measurement,and high-capacity optical communication,the output bandwidth and wavelength tunability of vortex beams have become a research focus.Breaking through the emission wavelength limitation of rare-earth doped fiber,and the device of broadband mode conversion is the basis for realizing the output of special band/broadband vortex light.Currently,many devices can realize vortex beam output in a fiber laser.However,most devices are designed and manufactured according to the target wavelength.The acoustically-induced fiber grating(AIFG)achieves mode conversion by acousto-optic coupling in passive fibers.When the operating wavelength changes,it only needs to change the frequency of the loaded electric signal,without re-designing and replacing the parameters of the mode conversion device.Theoretically,it has an extremely wide operating bandwidth.Considering the above requirements,the structure of random Raman fiber laser(RRFL)based on distributed Rayleigh backscattering is adopted to realize broadband vortex beams by combining the AIFG.Methods By combining the AIFG and RRFL,when the output wavelength is converted by Raman frequency shift,there is no need to redesign and replace the mode conversion device.The transmission spectrum of the LP01 mode is tested in Fig.1(b),which indicates that there is a high efficiency of mode conversion from 1000 to 1700 nm.The RRFL is built as shown in Fig.2.An amplified spontaneous emission(ASE)source including two amplification stages is utilized as the pump source which is then coupled into the half-open cavity of RRFL by wavelength division multiplexing(WDM).The half-open cavity is formed by a high-reflective(HR)optical fiber mirror which is attached to the WDM,a piece of gain fiber,and a homemade fiber endcap.The reflectance of the HR mirror is more than 99.5%at 1‒

关 键 词：随机拉曼光纤激光器 涡旋光束 声致光纤光栅 轨道角动量 

分 类 号：TN248[电子电信—物理电子学]