5 kW-level single-mode fiber amplifier based on low-numerical-aperture fiber  

作　　者：陈益沙 叶云 黄良金 杨欢 吴函烁 闫志平 潘志勇 王小林 王泽锋 周朴 Yisha Chen;Yun Ye;Liangjin Huang;Huan Yang;Hanshuo Wu;Zhiping Yan;Zhiyong Pan;Xiaolin Wang;Zefeng Wang;Pu Zhou(College of Advanced Interdisciplinary Studies,National University of Defense Technology,Changsha 410073,China;Nanhu Laser Laboratory,National University of Defense Technology,Changsha 410073,China;Hunan Provincial Key Laboratory of High Energy Laser Technology,National University of Defense Technology,Changsha 410073,China)

机构地区：[1]College of Advanced Interdisciplinary Studies,National University of Defense Technology,Changsha 410073,China [2]Nanhu Laser Laboratory,National University of Defense Technology,Changsha 410073,China [3]Hunan Provincial Key Laboratory of High Energy Laser Technology,National University of Defense Technology,Changsha 410073,China

出　　处：《Chinese Optics Letters》2024年第4期71-76,共6页中国光学快报（英文版）

基　　金：supported by the National Key R&D Program of China(No.2022YFB3606000);State Key Laboratory of Pulsed Power Laser Technology(No.SKL2021ZR06)。

摘　　要：A low-numerical-aperture(NA)concept enables large-mode-area fiber with better single-mode operation ability,which is beneficial for transverse mode instability and nonlinear effects suppression.In this contribution,we reported a high-power fiber amplifier based on a piece of self-developed large-mode-area low-NA fiber with a core NA of 0.049 and a core/inner cladding diameter of 25/400μm.The influence of the pump wavelength and fiber length on the power scaling potential of the fiber amplifier is systematically investigated.As a result,an output of 4.80 kW and a beam quality factor of~1.33 were finally obtained,which is the highest output power ever reported in a fiber amplifier exploiting the low-NA fiber.The results reveal that low-NA fibers have superiority in power scaling and beam quality maintenance at high power levels.

关 键 词：high power fiber lasers ytterbium-doped fiber low-numerical-aperture fiber mode instability 

分 类 号：TN248[电子电信—物理电子学] TN722