物理学报2024，Vol.73Issue(1)：101-112,12.DOI:10.7498/aps.73.20231085
百兆赫兹重频的轨道角动量模式飞秒光纤激光器
Orbital angular momentum mode femtosecond fiber laser with over 100 MHz repetition rate
摘要
Abstract
Orbital angular momentum(OAM)lasers have potential applications in large capacity communication systems,laser processing,particle manipulation and quantum optics.OAM mode femtosecond fiber laser has become the research focus due to the advantages of simple structure,low cost and high peak power.At present,OAM mode femtosecond fiber lasers have made some breakthroughs in key parameters such as repetition frequency,pulse width,spectrum width,but it is difficult to achieve good overall performance.Besides,the repetition rate is tens of MHz at present.In this paper,a large-bandwidth mode coupler is made based on the mode phase matching principle.In coupler,the first order mode coupler with 3 dB polarization dependent loss is made by the technology of strong fused biconical taper,and the second order mode coupler with 0.3 dB polarization dependent loss is made by the technology of weak fused biconical taper.By combining the nonlinear polarization rotation mode-locking mechanism,OAM mode femtosecond fiber laser with over 100 MHz repetition rate is built.The achievement of the key parameters is attributed to the selection of dispersion shifted fibers that can accurately adjust intracavity dispersion.Comparing with traditional dispersion compensation fibers(DCF),the group velocity dispersion is reduced by an order of magnitude,so it can better adjust intracavity dispersion to achieve the indexes of large spectral bandwidth and narrow pulse width.In addition,the diameter of the fiber is 8 μm,which is the same as that of a single mode fiber.Comparing with DCF,the fusion loss can be ignored,so only a shorter gain Erbium-doped fiber is required,which ensures a shorter overall cavity length and achieves high repetition frequency.The experimental results show that the first order OAM mode fiber laser has 113.6 MHz repetition rate,98 fs half-height full pulse width,and 101 nm 10 dB bandwidth.Second-order OAM mode fiber laser has 114.9 MHz repetition rate,60 fs half-height full pulse width,and 100 nm 10 dB bandwidth.Compared with the reported schemes,our scheme has good performance in key parameters such as repetition rate,pulse width and spectral width.We believe that the OAM mode fiber laser with excellent performance is expected to be widely used in OAM communication,particle manipulation and other research fields.关键词
光纤锁模激光器/轨道角动量/模式耦合器Key words
femtosecond fiber laser/orbital angular momentum/mode selective coupler引用本文复制引用
吴航,陈燎,李帅,杜禺璠,张驰,张新亮..百兆赫兹重频的轨道角动量模式飞秒光纤激光器[J].物理学报,2024,73(1):101-112,12.基金项目
国家自然科学基金(批准号:61505060,61631166003,61675081,61735006,61927817)资助的课题.Project supported by the National Natural Science Foundation of China(Grant Nos.61505060,61631166003,61675081,61735006,61927817). （批准号:61505060,61631166003,61675081,61735006,61927817）
