Brightness enhancement on a narrow-linewidth fiber Bragg grating-based master oscillator power amplification fiber laser  

作　　者：Xin Tian Binyu Rao Meng Wang Xiaoming Xi Zhixian Li Zilun Chen Hu Xiao Pengfei Ma Zefeng Wang 

机构地区：[1]College of Advanced Interdisciplinary Studies,National University of Defense Technology,Changsha,China [2]Nanhu Laser Laboratory,National University of Defense Technology,Changsha,China [3]Hunan Provincial Key Laboratory of High Energy Laser Technology,National University of Defense Technology,Changsha,China

出　　处：《High Power Laser Science and Engineering》2024年第4期56-64,共9页高功率激光科学与工程（英文版）

基　　金：supported by the Science and Technology Innovation Program of Hunan Province(No.2021RC4027)。

摘　　要：In this paper,we have experimentally demonstrated a high-power and high-brightness narrow-linewidth fiber amplifier seeded by an optimized fiber oscillator.In order to improve the temporal stability,the fiber oscillator consists of a composite fiber Bragg grating-based cavity with an external feedback structure.By optimizing the forward and backward pumping ratio,the nonlinear effects and stimulated Raman scattering-induced mode distortion of the fiber amplifier are suppressed comprehensively,accompanied with the simultaneous improvement of beam quality and output power.The laser brightness is enhanced further by raising the threshold of transverse mode instability by approximately 1.0 kW by coiling the gain fiber with a novel curvature shape.Finally,a 6 kW narrow-linewidth laser is achieved with beam quality(M^(2))of approximately 1.4.The laser brightness doubled compared to the results before optimization.To the best of our knowledge,it is the highest brightness narrow-linewidth fiber laser based on a one-stage master oscillator power amplification structure.

关 键 词：BRIGHTNESS fiber laser narrow linewidth ytterbium-doped fiber 

分 类 号：TN248[电子电信—物理电子学]