Yb-doped aluminophosphosilicate fiber amplifier with 244 pm linewidth and near diffraction limited beam quality for beam combination

• Published in: Optical fiber technology Vol. 74; p. 103115
• Main Authors: Sun, Shihao, Li, Fang, Gao, Cong, Chu, Qiuhui, Shen, Changle, Liu, Nian, Dai, Jiangyun, He, Honglei, Zhang, Lihua, Jiang, Lei, Lv, Jiakun, Jia, Baonan, Lu, Pengfei, Zheng, Ye, Wang, Junlong, Lin, Honghuan, Wang, Jianjun
• Format: Journal Article
• Language: English
• Published: Elsevier Inc 01.12.2022
• Subjects: Beam combination; Narrow linewidth; Near-diffraction-limited beam quality; Yb-doped silica fiber; Near-diffraction-limited beam quality; Narrow linewidth; Beam combination; Yb-doped silica fiber
• ISSN: 1068-5200; 1095-9912
• DOI: 10.1016/j.yofte.2022.103115

•Yb-doped fiber was fabricated with the same concentration ratio of Al/P.•The output power reached 1916 W, presenting an efficiency of 83.7 %.•Laser linewidth was hardly broadened with the 20 dB RMS of 0.244 nm.•The beam quality is near-diffraction-limited, with the M2 factor less than 1.27. Yb-doped aluminophosphosilicate fiber was fabricated by the combination system of chelate precursor doping technique and the modified chemical vapor deposition system. The technical details of the fabrication process were optimized to ensure the same elemental concentration ratio of Al/P. The capability of this fiber for the beam combining application was investigated based on a narrow linewidth fiber laser system. This fiber presented the output power of 1783 W with a slope efficiency of 83.7 % and a 20 dB root-mean-square linewidth of 0.244 nm with no nonlinear effects in the laser spectrum. Near-diffraction-limited beam quality was also observed with a M2 factor less than 1.27. In conclusion, this fiber presented an attractive laser performance for beam combination through the comprehensive optimization of fabrication technique and narrow linewidth laser system.