Affiliation:
1. Tianjin Key Laboratory of Special Optical Fiber Materials, The 46th Research Institute, China Electronics Technology Group Corporation, Tianjin 300220, China
Abstract
Photodarkening (PD) effect in ytterbium-doped fiber (YDF) has a significant impact on the high-power operational stability of fiber lasers, which seriously hinders the power scaling. In this paper, the relationship between ytterbium ions uniformity and the photodarkening effect in the YDF was investigated, and the fabrication process allowing improving the ytterbium ions uniformity in the core of preforms for suppressing the photodarkening effect was developed. The Modified Chemical Vapor Deposition (MCVD) method combined with Chelate Vapor Deposition (CVD) technology was adopted for multi-layer fiber core deposition, and an all-gas-phase technical process was proposed to improve the ytterbium ions uniformity in the Al/P co-doped glass matrix. The 25/400 μm YDFs obtained by this technology achieved stable 3.5 kW laser output power for 8 h with suppressed PD and nonlinear effects.
Funder
National Key R&D Program of China
Reference34 articles.
1. High power fiber lasers: Current status and future perspectives;Richardson;JOSA B,2010
2. Status and development tendency of high power ytterbium doped fibers;Yibo;Chin. J. Lasers,2017
3. Research progress on photodarkening of Yb-doped fiber lasers;Liu;Lasers Optoelectron. Prog.,2016
4. Zervas, M.N., Ghiringhelli, F., Durkin, M.K., and Crowe, I. (2011). Distribution of photodarkening-induced loss in Yb-doped fiber amplifiers. Fiber Lasers VIII: Technology, Systems, and Applications, SPIE.
5. Photodarkening and photobleaching of an ytterbium-doped silica double-clad LMA fiber;Boullet;Opt. Express,2007