In this paper, we demonstrate an ytterbium-doped all-fiber master-oscillator power amplifier (MOPA) system which uses a narrow-linewidth seed source, generating narrow-linewidth and high power continuous-wave output power at 1064nm. Our MOPA configuration system consist of three amplifier stages. We use single-mode Yb-doped fiber as the gain fiber in the first and second pre-amplifier stages, so it can keep good beam quality before entering the main amplifier stage. In order to raise the threshold of nonlinear effects, such as SBS and SRS, and to relieve heat effect, our high power system choose large mode area (LMA) fiber as the gain fiber in the main amplifier stage. For the sake of suppressing high-order modes in LMA fiber, we design novel watering cooling plates of different sizes, and using them in our main amplifier stage. By optimizing its structure, we get very good laser beam pattern on CCD at high power output. The beam quality factor (M²) was about 1.4 at 1.31 kW.

Date Published: 4 May 2015
PDF: 6 pages
Proc. SPIE 9543, Third International Symposium on Laser Interaction with Matter, 95431L (4 May 2015); doi: 10.1117/12.2181497

Published in SPIE Proceedings Vol. 9543:
Third International Symposium on Laser Interaction with Matter
Yury M. Andreev; Zunqi Lin III; Xiaowu Ni; Xisheng Ye, Editor(s)