A 7-kW narrow-linewidth fiber amplifier assisted by optimizing the refractive index of the large-mode-area active fiber

Pengfei Ma; Tianfu Yao; Wei Liu; Zhiyong Pan; Yisha Chen; Huan Yang; Zilun Chen; Zefeng Wang; Pu Zhou; Jinbao Chen

doi:10.1017/hpl.2024.41

High Power Laser Science and Engineering (Jan 2024)

A 7-kW narrow-linewidth fiber amplifier assisted by optimizing the refractive index of the large-mode-area active fiber

Pengfei Ma,
Tianfu Yao,
Wei Liu,
Zhiyong Pan,
Yisha Chen,
Huan Yang,
Zilun Chen,
Zefeng Wang,
Pu Zhou,
Jinbao Chen

Affiliations

Pengfei Ma: ORCiD; College of Advanced Interdisciplinary Studies, National University of Defense Technology, Changsha, China Nanhu Laser Laboratory, National University of Defense Technology, Changsha, China Hunan Provincial Key Laboratory of High Energy Laser Technology, National University of Defense Technology, Changsha, China
Tianfu Yao: College of Advanced Interdisciplinary Studies, National University of Defense Technology, Changsha, China Nanhu Laser Laboratory, National University of Defense Technology, Changsha, China Hunan Provincial Key Laboratory of High Energy Laser Technology, National University of Defense Technology, Changsha, China
Wei Liu: ORCiD; College of Advanced Interdisciplinary Studies, National University of Defense Technology, Changsha, China Nanhu Laser Laboratory, National University of Defense Technology, Changsha, China Hunan Provincial Key Laboratory of High Energy Laser Technology, National University of Defense Technology, Changsha, China
Zhiyong Pan: College of Advanced Interdisciplinary Studies, National University of Defense Technology, Changsha, China Nanhu Laser Laboratory, National University of Defense Technology, Changsha, China Hunan Provincial Key Laboratory of High Energy Laser Technology, National University of Defense Technology, Changsha, China
Yisha Chen: ORCiD; College of Advanced Interdisciplinary Studies, National University of Defense Technology, Changsha, China Nanhu Laser Laboratory, National University of Defense Technology, Changsha, China Hunan Provincial Key Laboratory of High Energy Laser Technology, National University of Defense Technology, Changsha, China
Huan Yang: College of Advanced Interdisciplinary Studies, National University of Defense Technology, Changsha, China Nanhu Laser Laboratory, National University of Defense Technology, Changsha, China Hunan Provincial Key Laboratory of High Energy Laser Technology, National University of Defense Technology, Changsha, China
Zilun Chen: College of Advanced Interdisciplinary Studies, National University of Defense Technology, Changsha, China Nanhu Laser Laboratory, National University of Defense Technology, Changsha, China Hunan Provincial Key Laboratory of High Energy Laser Technology, National University of Defense Technology, Changsha, China
Zefeng Wang: ORCiD; College of Advanced Interdisciplinary Studies, National University of Defense Technology, Changsha, China Nanhu Laser Laboratory, National University of Defense Technology, Changsha, China Hunan Provincial Key Laboratory of High Energy Laser Technology, National University of Defense Technology, Changsha, China
Pu Zhou: ORCiD; College of Advanced Interdisciplinary Studies, National University of Defense Technology, Changsha, China
Jinbao Chen: College of Advanced Interdisciplinary Studies, National University of Defense Technology, Changsha, China Nanhu Laser Laboratory, National University of Defense Technology, Changsha, China Hunan Provincial Key Laboratory of High Energy Laser Technology, National University of Defense Technology, Changsha, China

DOI: https://doi.org/10.1017/hpl.2024.41
Journal volume & issue: Vol. 12

Abstract

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The high-power narrow-linewidth fiber laser has become the most widely used high-power laser source nowadays. Further breakthroughs of the output power depend on comprehensive optimization of stimulated Brillouin scattering (SBS), stimulated Raman scattering (SRS) and transverse mode instability (TMI). In this work, we aim to further surpass the power record of all-fiberized and narrow-linewidth fiber amplifiers with near-diffraction-limited (NDL) beam quality. SBS is suppressed by white-noise-signal modulation of a single-frequency seed. In particular, the refractive index of the large-mode-area active fiber in the main amplifier is controlled and fabricated, which could simultaneously increase the effective mode field area of the fundamental mode and the loss coefficient of higher-order modes for balancing SRS and TMI. Subsequent experimental measurements demonstrate a 7.03 kW narrow-linewidth fiber laser with a signal-to-noise ratio of 31.4 dB and beam quality factors of Mx 2 = 1.26, My 2 = 1.25. To the best of our knowledge, this is the highest reported power with NDL beam quality based on a directly laser-diode-pumped and all-fiberized format, especially with narrow-linewidth spectral emission.

Published in High Power Laser Science and Engineering

ISSN: 2095-4719 (Print); 2052-3289 (Online)
Publisher: Cambridge University Press
Country of publisher: United Kingdom
LCC subjects: Technology: Engineering (General). Civil engineering (General): Applied optics. Photonics
Website: https://www.cambridge.org/core/journals/high-power-laser-science-and-engineering

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