主动调Q掺镱光纤激光器中放大自发辐射影响的研究  

Study on Influences of Amplified Spontaneous Emission on Actively Q-Switched Ytterbium-Doped Fiber Laser

作　　者：陈晓东[1,2] 孙青[1,3] 赵佳生[1] 冯素娟[1] 毛庆和[1] 

机构地区：[1]中国科学院安徽光学精密机械研究所安徽省光子器件与材料重点实验室,安徽合肥230031 [2]解放军电子工程学院光电系脉冲功率激光技术国家重点实验室,安徽合肥230037 [3]中国计量科学研究院光学与激光计量研究所,北京100013

出　　处：《中国激光》2010年第8期1929-1933,共5页Chinese Journal of Lasers

基　　金：国家自然科学基金(60677050);国家973计划(2007CB936603)资助课题

摘　　要：实验研究了主动调Q掺镱光纤激光器(YDFL)中放大自发辐射(ASE)对调Q脉冲形成和演化的影响。结果表明,尾纤型声光调制器(AOM)打开过快和掺镜光纤(YDF)增益瞬态特性间的综合相互作用结果,使得注入至腔内的初始宽带ASE形成功率波动,并在腔内循环放大,导致输出脉冲呈多峰结构;而注入的宽带ASE因功率过高会导致YDF的增益自饱和效应,制约高增益的获取,使激光器难以获得调Q激光脉冲,输出脉冲主要为调Q的ASE脉冲;通过引入光纤布拉格光栅(FBG),可以有效抑制YDF中因ASE产生的增益饱和效应,YDF工作在高增益状态,有利于获得低阈值、窄脉宽和高峰值功率的调Q激光脉冲。引入FBG后,在160 mW抽运时,实验测得的调Q激光脉冲峰值功率和脉宽分别为40.7 W和30 ns。The influences of amplified spontaneous emission（ASE） on the formation and evolution of pulses in actively Q-switched ytterbium-doped fiber laser（YDFL） are investigated experimentally.The experimental results show that the combined effect between the short switching time and the gain transient property of ytterbium-doped fiber（YDF） causes the initial ASE power fluctuation,which then forms the multi-peak structure in the output pulse after having been circulated and amplified in the cavity.Meanwhile,the high-level broadband ASE may give rise to the gain self-saturation effect in the YDF,making it difficult to form Q-switched laser pulses for the fiber laser.The output pulses may be eventually Q-switched ASE pulses,giving lower peak-power and larger pulse duration.By using fiber Bragg grating（FBG） to suppress the gain self-saturation effect,the gain supplied by the YDF can be greatly enhanced,making it easy for the laser to achieve the Q-switched laser pulse with low threshold,small duration,and high peak-power.When the YDFL with FBG is pumped with 160 mW,the Q-switched laser pulses with the peak power of 40.7 W and the duration of 30 ns are achieved.

关 键 词：激光器 掺镱光纤 主动调Q 放大自发辐射 线形腔 

分 类 号：TN253[电子电信—物理电子学] TN248.1