Design and optimization methods towards a 10 kW high beam quality fiber laser based on the counter tandem pumping scheme
Ruixian Li, Hanshuo Wu, Hu Xiao, Zilun Chen, Jinyong Leng, Liangjin Huang, Zhiyong Pan, Pu Zhou
Abstract
Abstract In this study, we investigated the influence of fiber parameters on stimulated Raman scattering (SRS) and identified a unique pattern of SRS evolution in the counter tandem pumping configuration. Our findings revealed that the SRS threshold in counter-pumping is predominantly determined by the length of the output delivery fiber rather than the gain fiber. By employing the counter tandem pumping scheme and optimizing the fiber parameters, a 10 kW fiber laser was achieved with beam quality M 2 of 1.92. No mode instability or severe SRS limitation was observed. To our knowledge, this study achieved the highest beam quality in over 10 kW fiber lasers based on conventional double-clad Yb-doped fiber.