Abstract

Recent years have witnessed much progress in the development of fiber lasers in the 2 μm region. Yet, to date, their power levels are limited by modulation instability and soliton formation attributed to the strong anomalous dispersions of fused silica in this wavelength region. Further power scaling requires a novel design of an all-solid silica active fiber that features normal dispersion by compensating the material dispersion with the waveguide dispersion. At the same time, a large mode area, low losses, single mode operation and robustness need to be maintained. In this paper, we propose an all-solid anti-resonant fiber (AS-ARF) design that meets these demands. We demonstrate that normal dispersion can be achieved in AS-ARFs at 2 μm by exploiting the Kramers-Kronig relation. To balance the desired dispersion with the other performance parameters, we optimize the design of the AS-ARFs using a genetic algorithm. The optimized AS-ARF has a mode field area of 1170 μm² and normal dispersion over the spectrum from 1.96 μm to 2.04 μm. Within this spectrum, the maximum confinement loss (CL) of the fundamental mode (FM) is 16 dB/km and the minimum CL of the higher order modes (HOMs) is over 100 dB/km. The HOMs can be easily coupled out by bending the fiber while the FM stays in the core. For example, the CLs are over 2 × 10⁴ dB/km for the HOMs and below 200 dB/km for the FM at 2 μm at a bending radius of 20 cm. Moreover, the properties of the proposed AS-ARF remain favorable even under large geometric variations, showing good tolerance to manufacturing errors. We expect the proposed AS-ARF to further stimulate the development of high-power fiber lasers in the 2 μm region.

Large mode-area all-solid anti-resonant fiber based on chalcogenide glass for mid-infrared transmission

Lelu He, Yachen Liang, Yongnian Guan, Zhengxiang Gu, Kelun Xia, Xunsi Wang, Shixun Dai, Xiang Shen, and Zijun Liu
Opt. Express 31(5) 8975-8986 (2023)

Large-mode-area all-solid anti-resonant fiber with single-mode operation for high-power fiber lasers

Zhen Xing, Xin Wang, Shuqin Lou, Zijuan Tang, Haoqiang Jia, Shuai Gu, and Jihong Han
Opt. Lett. 46(8) 1908-1911 (2021)

Low bending loss and effectively single-mode all-solid photonic bandgap fiber with an effective area of 650 μm²

Masahiro Kashiwagi, Kunimasa Saitoh, Katsuhiro Takenaga, Shoji Tanigawa, Shoichiro Matsuo, and Munehisa Fujimaki
Opt. Lett. 37(8) 1292-1294 (2012)

Effectively single-mode all-solid photonic bandgap fiber with large effective area and low bending loss for compact high-power all-fiber lasers

Masahiro Kashiwagi, Kunimasa Saitoh, Katsuhiro Takenaga, Shoji Tanigawa, Shoichiro Matsuo, and Munehisa Fujimaki
Opt. Express 20(14) 15061-15070 (2012)

Design of all-solid leakage channel fibers with large mode area and low bending loss

Kunimasa Saitoh, Yukihiro Tsuchida, Lorenzo Rosa, Masanori Koshiba, Federica Poli, Annamaria Cucinotta, Stefano Selleri, Mrinmay Pal, Mukul Paul, Debashri Ghosh, and Shyamal Bhadra
Opt. Express 17(6) 4913-4919 (2009)