Gaussian-Shaped Gain-Dopant Distributed Fiber for High Output Power Fiber Amplifier

• Published in: IEEE photonics journal Vol. 13; no. 4; pp. 1 - 6
• Main Authors: Zhang, Zhilun, Lin, Xianfeng, Chen, Gui, Liao, Lei, Xing, Yingbin, Li, Haiqing, Peng, Jinggang, Dai, Nengli, Li, Jinyan
• Format: Journal Article
• Language: English
• Published: Piscataway IEEE 01.08.2021; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Amplification; Chemical vapor deposition; Dopants; doped fiber amplifiers. transverse mode instability; Doped fibers; Fiber lasers; Ions; Laser beams; Laser outputs; Normal distribution; Optical fiber amplifiers; Optical fiber couplers; Power amplifiers; Power generation; Refractivity; Soot; Ytterbium
• ISSN: 1943-0655; 1943-0655; 1943-0647
• DOI: 10.1109/JPHOT.2021.3096716

The remarkable evolution of ytterbium-doped fiber (YDF) lasers and amplifiers is interrupted by a limiting thermo-optical effect called transverse mode instability (TMI). Hereon, we propose a Gaussian-shaped gain-dopant distributed (GSGDD) YDF, which is fabricated by a modified chemical vapor deposition (MCVD) process combined with solution doping technique (SDT). By regulating the solution concentrations of soot layers, the content of Yb 3+ ions presents Gaussian-shaped distribution in the transverse direction while the refractive index profile (RIP) exhibits a stepped profile. The laser performance of this fiber is verified by a bidirectional pumped master oscillator power amplifier (MOPA). Over 3 kW near-single-mode laser output is obtained with the slope efficiency of 84.9%. At the highest power output, there are no Stokes light components in the spectrum and the beam quality M 2 factor is ∼1.45 These results suggest that the GSGDD fiber owns great potential to achieve high power output with excellent beam quality.