基于自反馈光注入结构的双波长可调谐掺Er^3＋光纤激光器  

A tunable dual-wavelength Er^(3+)-doped fiber laser based on selffeedback light injection

作　　者：何巍[1,2] 祝连庆[1,2] 娄小平[2] 董明利[2] 张荫民[2] 骆飞[2] 陈晓怀[1] 

机构地区：[1]合肥工业大学仪器科学与光电工程学院,安徽合肥230009 [2]北京信息科技大学光电信息与仪器北京市工程研究中心,光电测试技术北京市重点实验室,北京100192

出　　处：《光电子．激光》2014年第6期1080-1085,共6页Journal of Optoelectronics·Laser

基　　金：北京市重大科技计划项目(PXM2013_014224_000077,PXM2012_014224_000019);光电信息与仪器北京市工程研究中心开放课题(GD20130006)资助项目

摘　　要：为了实现可调谐双波长激光输出,提出并设计了一种基于自反馈光注入结构的掺Er3+光纤(EDF)激光器,并对激光器的基本原理及实现方案进行了理论分析和实验验证。系统结构设计采用976nm波长的LD作为泵浦源,结合EDF,两支光纤布拉格光栅(FBG)和光纤环形镜(FLM)产生激光,并通过在FLM中熔接饱和吸收体(SA)起到稳频作用;将FLM输出激光耦合进入谐振腔形成自注入结构,与腔内振荡激光形成干涉,抑制模式跳变;通过控制两支FBG之间的可调谐衰减器调节谐振腔内的增益和损耗,实现单个波长或双波长输出。实验结果表明:SA长采用4m、EDF长采用6m时,激光输出阈值为28mW,将反馈光注入谐振腔后,系统阈值为25mW,输出激光波长随时间漂移得到明显抑制;当泵浦光功率为80mW时,通过调节位于两支FBG之间的可调谐衰减器(VA)获得稳定的双波长激光输出;随着泵浦功率增加,激光输出功率具有良好的线性度和稳定性。在1 540nm波长处激光输出最大功率为1.16mW,信噪比(SNR)大于50dB;在1 545nm波长处激光输出最大功率为1.89mW,SNR大于50dB。In order to realize a tunable dual-wavelength laser output,an Er3＋-doped fiber laser based on self-feedback light injection is proposed,and the theoretical analysis and experimental verification are presented in detail.In the designed configuration,one 976nm laser diode（LD）is used for pumping,Er3＋-doped fiber（EDF）is adopted as the gain medium,the laser cavity is composed of a fiber loop mirror（FLM）and two FBGs,and a saturable absorber（SA）is used to improve the output laser stability.In order to improve the laser stability and restrain the mode hopping,the output laser from FLM is used as self-feedback light which is coupled into the cavity by a 90∶10coupler.The interference is shown when injection light and oscillating light transmit in the cavity,a weak Bragg grating is generated and some certain waves can be restrained,so that a fiber laser with stable output is achieved.A switchable single-wavelength and dual-wavelength laser is achieved by adjusting the variable attenuator between two FBGs.In the experiment,an EDF of 4mlength is selected as the SA,and an EDF of 6mlength is adopted as the gain medium.In the end,the threshold is reduced from 28 mW to 25 mW after self-feedback light is injected into the cavity.When pump power is 80 mW,a stable tunable dual-wavelength output is realized by adjusting the variable attenuator（VA）.When the pump power is improved,the single wavelength laser at 1 540 nm and 1 545 nm is measured and the power is 1.16 mW and 1.89 mW,respectively,and the SNRis greater than 50 dB.A stable and tunable dual-wavelength Er3＋-doped fiber laser is achieved by self-feedback light injection structure and SA,which can optimize the system and improve the working efficiency.

关 键 词：双波长光纤激光器 自反馈光注入 掺Er^3+光纤(EDF) 饱和吸收体(SA) 

分 类 号：O433[机械工程—光学工程]