双端输出近单模准连续全光纤激光器  

Double-ended output near-single-mode quasi-continuous wave monolithic fiber laser

作　　者：丁欣怡 王力 曾令筏 吴函烁 王小林[1,3] 宁禹 习锋杰[1,3] Ding Xin-Yi;Wang Li;Zeng Ling-Fa;Wu Han-Shuo;Wang Xiao-Lin;Ning Yu;Xi Feng-Jie(College of Advanced Interdisciplinary Studies,National University of Defense Technology,Changsha 410073,China;School of Optoelectronic Science and Engineering,University of Electronic Science and Technology of China,Chengdu 611731,China;Nanhu Laser Laboratory,National University of Defense Technology,Changsha 410073,China)

机构地区：[1]国防科技大学前沿交叉学科学院,长沙410073 [2]电子科技大学光电科学与工程学院,成都611731 [3]国防科技大学南湖之光实验室,长沙410073

出　　处：《物理学报》2023年第15期83-91,共9页Acta Physica Sinica

基　　金：湖南省杰出青年基金(批准号:2023JJ10057)资助的课题.

摘　　要：准连续光纤激光器在工业领域有着广阔的应用前景,双端输出结构为工业低成本高功率光纤激光器提供了新思路,提出并研究了双端输出准连续光纤激光器.基于稳态速率方程,建立了双端准连续光纤激光振荡器的理论模型,对该类型激光器的输出功率、时序及非线性效应进行了仿真研究.结果表明:延长泵浦上升时间可以有效抑制弛豫振荡,在脉冲持续时间内获得稳定的输出;双端输出准连续激光器相比单端输出结构,非线性效应累积更小.实验采用纤芯/包层直径为20/400μm的掺镱光纤,首次实现了峰值功率3 kW的双端准连续近单模激光输出,两端峰值功率分别为1218和2220 W,对应光束质量因子M^(2)分别为1.34和1.27,光光转换效率约为60%,脉宽为100μs,重频为1 kHz.验证了双端输出准连续光纤激光器实现高功率、高光束质量输出的可行性,为小体积、低成本、高功率和高亮度的准连续光纤激光器提供了支撑.Quasi-continuous fiber lasers have a broad application prospect in the industrial field.However,in the current research on quasi-continuous wave(QCW)fiber lasers only the single-ended output structure is used.A double-ended output fiber laser oscillator needs only one resonator to realize two laser outputs.Compared with single-ended output laser,it has a low cost,small volume and high work efficiency.It is expected to achieve higher power laser output through double-ended output beam combining.Therefore,the double-ended output QCW fiber laser is proposed and studied in this paper.The steady-state rate equation establishes a theoretical model of a QCW fiber laser oscillator with two ends,considering the stimulated Raman scattering(SRS)and amplified spontaneous emission(ASE).The output power,time domain and nonlinear effects of this type of laser are simulated.The results show that the overshoot effect caused by relaxation oscillation will produce a large amount of thermal deposition and ultra-high peak power in the fiber.It will reduce the nonlinear threshold and limit the increase of power of the QCW fiber laser.Prolonging the rise time of the pump can effectively suppress the relaxation oscillation and obtain a stable pulse output during the pulse duration.In addition,compared with the single-ended QCW laser,the double-ended output structure changes the energy distribution in the fiber and reduces the accumulation of nonlinear effects in the gain fiber,thus inhibiting SRS.Then,the ytterbium-doped fiber with a core/cladding diameter of 20/400μm is used to achieve the first double-ended QCW laser output with a peak power of 3 kW.The peak power values at both ends are 1218 and 2220 W,respectively.The values of corresponding beam quality factor M2 are 1.34 and 1.27.The optical-to-optical conversion efficiency is about 60%.The pulse width is 100μs,and the repetition frequency is 1 kHz.This research verifies the feasibility of high power and high beam quality output by double-ended output QCW fiber laser,which provi

关 键 词：光纤激光 准连续 双端输出 近单模 

分 类 号：TN248[电子电信—物理电子学]