CAJ | 학술논문

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。
재광빈적절대측량연구중，본연구소조연제료광보범위위650~950 nm파단、중복빈솔위350 MHz적“단괴”결구태보석비초격광빈솔소。위료실현기대633 nm파장국가부기준빈솔적절대측량，본실험분별채용릉경대화조추경대진행맥관압축，연후주입광자정체광섬진행광보확전。실험발현량자균가확전출단파장방향적광보，단릉경대확보결구유우구유교장적“광정비장”용역수도우동이조성광섬우합적불은정，최종표현위광보중각파장성분적광강불은정이무법용우광빈측량。조추경대결구긴주、은정성강，경과맥관압축급광자정체광섬확보，최종획득료광보복개600~950 nm파단、각파장성분강도은정、각광빈치빈솔은정도동보우경원자종적가용우광빈측량적비초격광빈솔소。
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.