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 higher-order modes into the cladding. A series of fibers with core sizes ranging from 40 to 100 µm are proposed exhibiting maximum mode area exceeding 5000 µm2. Numerical simulations show this resonant coupling scheme provides a higher-order modes (HOMs) (mainly TE01, TM01 and HE02) suppression ratio 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.
Zhang Xin, Gao Shoufei, Wang Yingying, Ding Wei, Wang Pu. Design of Large Mode Area All-Solid Anti-Resonant Fiber for High Power Lasers[J]. High Power Laser Science and Engineering, , (): .
