基于全保偏光纤的宽带宽调谐DFG中红外光梳  

Mid-Infrared DFG Comb with Broadband and Wide Tunable Range Based on All Polarization-Maintaining Fibers

作　　者：马挺 路桥 赵晨亮 马金栋 毛庆和 Ma Ting;Lu Qiao;Zhao Chenliang;Ma Jindong;Mao Qinghe(Anhui Provincial Key Laboratory of Photonics Devices and Materials,Anhui Institute of Optics and Fine Mechanics,Hefei Institutes of Physical Science,Chinese Academy of Sciences,Hefei 230031,Anhui,China;University of Science and Technology of China,Hefei 230026,Anhui,China;Advanced Laser Technology Laboratory of Anhui Province,Hefei 230037,Anhui,China)

机构地区：[1]中国科学院合肥物质科学研究院,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]中国科学技术大学,安徽合肥230026 [3]先进激光技术安徽省实验室,安徽合肥230037

出　　处：《中国激光》2023年第23期72-79,共8页Chinese Journal of Lasers

基　　金：国家重点研发计划(2017YFB0405100,2017YFB0405200);中国科学院战略性先导科技专项(B类)(XDB21010300)。

摘　　要：本文报道了一种性能稳定的宽带宽调谐差频产生(DFG)中红外光梳设计方案。采用保偏光纤构建光纤链路,以确保其性能稳定;采用自相似光纤放大、光纤孤子压缩及负色散高非线性光纤产生超连续谱等技术,获得了宽带、弱啁啾和窄脉宽基频脉冲;通过严格控制双色基频脉冲的空间重叠、时间同步和偏振特性,仅通过调整硒化镓非线性晶体的相位匹配角和时间同步,无须改变双色基频频率的光谱特性,DFG中红外光梳就可以实现宽光谱带宽和宽光谱调谐范围输出。集成封装仪器化的DFG中红外光梳的光谱覆盖范围为7~13μm,每个调谐波段的带宽均较宽,9.5μm波段的带宽达到了2.43μm;7~13μm光谱调谐范围内的平均功率都大于240μW,其中8μm波段的平均功率达到了470μW。Objective Mid-infrared optical frequency combs are widely used in precision spectroscopy,optical frequency metrology,instrument calibration,and other fields.Fiber-type dual-arm structure difference frequency generation(DFG)mid-infrared combs based on mode-locked fiber lasers are currently the primary technology for generating mid-infrared combs.The spectral tuning range and spectral bandwidth are two key indicators of DFG mid-infrared combs.The spectral tuning range is ensured by the wide tuning range of the fundamental frequency pulse,and the spectral bandwidth is associated with the crystal phase-matching acceptance bandwidth and the spectral width of the fundamental frequency pulse.Generally,the fundamental frequency pump pulse is generated by directly amplifying the oscillator output pulse,whereas the fundamental frequency signal pulse is obtained by amplifying and compressing the output pulse of the oscillator and then pumping a highly nonlinear fiber(HNLF)to generate long-wave frequency shift solitons.Although many reports on wide-tunable DFG mid-infrared combs exist,the bandwidth of two-color fundamental frequency pulses is narrow,owing to the limitation of the gain bandwidth of fiber amplifiers,and thus limits the bandwidth of the generated DFG mid-infrared combs.Therefore,the generation of a fundamental frequency pulse with a wider spectrum to obtain DFG mid-infrared combs with larger bandwidths and tuning ranges as well as the design and development of a practical light source device requires further research.Methods A fully polarization-maintaining 9-cavity fiber laser was used as the pulse source,and the repetition frequency was locked to the rubidium atomic clock through a servo feedback loop.The output of the oscillator was filtered and shaped and further divided into two paths using an optical coupler(OC)after erbium-doped fiber amplification(EDFA-1).It was then amplified by self-similarity fiber amplifiers EDFA-2 and EDFA-3.The EDFA-3 output pulse after being compressed serves as fundamental frequ

关 键 词：激光器 光学频率梳 差频产生 飞秒脉冲 中红外光梳 

分 类 号：O437[机械工程—光学工程]