光频测量用飞秒激光频率梳光谱扩展实验研究  

Research on Spectrum Expanding of a Femtosecond Optical Synthesizer for Absolute Frequency Measurement

作　　者：张大鹏[1] 梁志国[1] 叶蓬[2] 

机构地区：[1]中航工业北京长城计量测试技术研究所,北京100095 [2]中国科学院物理研究所,北京100080

出　　处：《计测技术》2014年第3期43-46,61,共5页Metrology & Measurement Technology

基　　金：国家"十一五"计划重点科研项目(A类)(07A401008)

摘　　要：在光频的绝对测量研究中，本研究小组研制了光谱范围为650~950 nm波段、重复频率为350 MHz的“单块”结构钛宝石飞秒激光频率梳。为了实现其对633 nm波长国家副基准频率的绝对测量，本实验分别采用棱镜对和啁啾镜对进行脉宽压缩，然后注入光子晶体光纤进行光谱扩展。实验发现两者均可扩展出短波长方向的光谱，但棱镜对扩谱结构由于具有较长的“光程臂长”容易受到扰动而造成光纤耦合的不稳定，最终表现为光谱中各波长成分的光强不稳定而无法用于光频测量。啁啾镜对结构紧凑、稳定性强，经过脉宽压缩及光子晶体光纤扩谱，最终获得了光谱覆盖600~950 nm波段、各波长成分强度稳定、各光频齿频率稳定度同步于氢原子钟的可用于光频测量的飞秒激光频率梳。A femtosecond laser optical synthesizer, with the repetition frequency of 350 MHz, whose spectrum bandwidth is from 650 nm to 950 nm, was developed for absolute frequency measurement. In order to measure the frequency of the national assistant wavelength reference, io-dine-stabilized 633 nm He-Ne laser, we must expand its spectrum to contain 633 nm wavelength. After compressing the pulse duration by the prism pair and chirped mirror pair, the laser pulses were focused into the photonic crystal fiber. But the intensity of the expanded spectrum gener-ated by prism pair changed rulelessly, because of the interfere of the environment. The chirped mirror pair, which is more compacted, could o-vercome this disadvantage. The broadband width spectrum after the chirped mirror pair and the photonic crystal fiber was steady for 5 hours, mo-nitored continuously by the spectrum suit, which is suitable for optical frequency measurement.

关 键 词：光频绝对测量 飞秒激光频率梳 光谱扩展 

分 类 号：TB96[机械工程—光学工程] TN24[一般工业技术—计量学]