12 March 2014 Effective mitigation of photodarkening in Yb-doped lasers based on Al-silicate using UV/visible light
Author Affiliations +
Abstract
In this work we discuss the impact of visible light radiation on photodarkening generation in 1070-nm Yb-doped fiber lasers. Simultaneous photodarkening and photobleaching effects induced by 976 nm and 405 nm or 550 nm radiations respectively were investigated. We observed a significant photobleaching effect due to 405 nm radiation but not a complete recovery. A strong absorption of the 405 nm radiation by the excited ions (Excited-State Absorption) was also observed and found as a main limiting factor for the bleaching performance together with observation of photodarkening losses induced by ground-state absorption. To proper define the optimum bleaching wavelength we report, for the first time to the best of our knowledge, the Excited-State Absorption cross section in the visible range. The reported experiments allow to individuate the main parameters defining the optimum bleaching wavelength. In a final experiment, using optimized 550-nm wavelength bleaching radiation, we were able to operate a laser at 93% of its pristine power level compensating a power drop of about 45% in absence of bleaching. The method we present is an effective yet simple way to run laser using standard Al-silicate fibers with doping level over 1026 ions/m3 and high inversion.
© (2014) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Riccardo Piccoli, Riccardo Piccoli, Thierry Robin, Thierry Robin, David Méchin, David Méchin, Thomas Brand, Thomas Brand, Udo Klotzbach, Udo Klotzbach, Stefano Taccheo, Stefano Taccheo, } "Effective mitigation of photodarkening in Yb-doped lasers based on Al-silicate using UV/visible light", Proc. SPIE 8961, Fiber Lasers XI: Technology, Systems, and Applications, 896121 (12 March 2014); doi: 10.1117/12.2039013; https://doi.org/10.1117/12.2039013
PROCEEDINGS
6 PAGES


SHARE
Back to Top