High Power Narrow-Linewidth Fiber Laser Based on Double-Tapered Fiber

• Published in: Journal of lightwave technology Vol. 40; no. 16; pp. 5668 - 5672
• Main Authors: Song, Jiaxin, Ren, Shuai, Wang, Guangjian, Yang, Huan, Chen, Yisha, Ma, Pengfei, Liu, Wei, Huang, Liangjin, Pan, Zhiyong, Zhou, Pu
• Format: Journal Article
• Language: English
• Published: New York IEEE 15.08.2022; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Amplifiers; Doped fibers; Double-tapered fiber; fiber laser; Fiber lasers; high power; Laser applications; Laser beams; Laser modes; narrow-linewidth; Optical fiber amplifiers; Optical fiber devices; Power amplifiers; Power generation
• ISSN: 0733-8724; 1558-2213
• DOI: 10.1109/JLT.2022.3183364

A homemade double-tapered Yb-doped fiber is employed in a high-power narrow-linewidth fiber amplifier to improve the thresholds of nonlinear effects and transverse mode instability (TMI) effect. A bidirectional pumping configuration is employed, and a phase-modulated single-frequency fiber laser serves as the seed laser. As a result, an output power of 3630 W with 0.21 nm linewidth (stimulate Brillouin scattering limited) and an output power of 4180 W with 0.59 nm linewidth (TMI limited) are realized, corresponding to the slope efficiency of ∼77%. The beam quality at the maximum output power is <inline-formula><tex-math notation="LaTeX">{\rm M}_{\rm x}^{2}= 1.57, {\rm M}_{\rm y}^{\rm 2} = 1.39</tex-math></inline-formula>. The results could provide a well reference for the power scaling of narrow-linewidth Yb-doped fiber amplifier.