摘要
High-power fiber lasers have experienced a dramatic development over the last decade.Further increasing the output power needs an upscaling of the fiber mode area,while maintaining a single-mode output.Here,we propose an all-solid anti-resonant fiber(ARF)structure,which ensures single-mode operation in broadband by resonantly coupling higherorder modes into the cladding.A series of fibers with core sizes ranging from 40 to 100µm are proposed exhibiting maximum mode area exceeding 5000µm2.Numerical simulations show this resonant coupling scheme provides a higher-order mode(mainly TE01,TM01,and HE21)suppression ratio of more than 20 dB,while keeping the fundamental mode loss lower than 1 dB/m.The proposed structure also exhibits high tolerance for core index depression.
基金
the National Research and Development Program of China(No.2017YFB0405200)
National Natural Science Foundation of China(Nos.61675011,61827820,61527822,and 61535009)
Beijing Nova Program(No.Z181100006218097)
Research Program of Beijing Municipal Education Commission(No.KZ201810005003)
State Key Laboratory of Advanced Optical Communication Systems and Networks,China.