Long D A, Fleisher A J, Plusquellic D F, Hodges J T
Material Measurement Laboratory, National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, Maryland 20899, USA.
Physical Measurement Laboratory, National Institute of Standards and Technology, 325 Broadway, Boulder, CO 80305, USA.
Phys Rev A (Coll Park). 2016 Dec;94(6). doi: 10.1103/PhysRevA.94.061801. Epub 2016 Dec 13.
An optical frequency comb generated with an electro-optic phase modulator and a chirped radiofrequency waveform is used to perform pump-probe spectroscopy on the and transitions of atomic potassium at 770.1 nm and 766.7 nm, respectively. With a comb tooth spacing of 200 kHz and an optical bandwidth of 2 GHz the hyperfine transitions can be simultaneously observed. Interferograms are recorded in as little as 5 μs (a timescale corresponding to the inverse of the comb tooth spacing). Importantly, the sub-Doppler features can be measured as long as the laser carrier frequency lies within the Doppler profile, thus removing the need for slow scanning or knowledge of the frequencies of the sub-Doppler features. Sub-Doppler optical frequency comb spectroscopy has the potential to dramatically reduce acquisition times and allow for rapid and accurate assignment of complex molecular and atomic spectra which are presently intractable.
利用电光相位调制器和啁啾射频波形产生的光学频率梳，分别对原子钾在770.1纳米和766.7纳米处的跃迁进行泵浦 - 探测光谱分析。梳齿间距为200千赫兹，光学带宽为2吉赫兹时，可同时观测到超精细跃迁。干涉图记录时间短至5微秒（这一时间尺度与梳齿间距的倒数相对应）。重要的是，只要激光载波频率位于多普勒轮廓内，就可以测量亚多普勒特征，从而无需进行缓慢扫描或了解亚多普勒特征的频率。亚多普勒光学频率梳光谱有潜力大幅缩短采集时间，并能快速准确地识别目前难以处理的复杂分子和原子光谱。
