论文标题
宽带高分辨率分子光谱与交织的中红外频率梳
Broadband high-resolution molecular spectroscopy with interleaved mid-infrared frequency combs
论文作者
论文摘要
从历史上看，高光谱分辨率，宽带覆盖范围和获取时间之间的光谱测量取舍。目前通常用于以卓越的准确性，分辨率和速度探测紫外原子原子原子氢原子的精确光谱的光学梳子，以探测分子旋转振动的转变。在这里，我们通过连续波长范围（频率跨度为1200 cm^{ - 1}，分辨率<100 kHz）在连续波长范围内获得250万个光谱点，该光谱点是通过与高度固定的宽带双频率固定系统获得的，基于光学上的宽带双重固定系统，该光谱通过梳子齿状分辨率<100 kHz）。借助115 MHz的原始梳子线间距，用逐渐移动的梳子线覆盖光谱，我们完全解析了具有狭窄多普勒 - 宽线的分子的分子的相位光谱，例如cS2碳二硫化物（CS2）及其同位素学。另外，我们能够通过通过其不对称ν3拉伸带检测羰基硫化物（OC）的痕迹来观察CS2的化学氧化反应。
Historically, there has been a trade-off in spectroscopic measurements between high spectral resolution, broadband coverage, and acquisition time. Optical frequency combs, initially envisioned for precision spectroscopy of the hydrogen atom in the ultraviolet region, are now commonly used for probing molecular rotational-vibrational transitions throughout broad spectral bands in the mid-infrared with superior accuracy, resolution and speed. Here we demonstrate acquisition of 2.5 million spectral points over the continuous wavelength range of 3.2 to 5.1 microns (frequency span 1200 cm^{-1}, resolution <100 kHz) via interleaving comb-tooth-resolved spectra acquired with a highly-coherent broadband dual-frequency-comb system based on optical subharmonic generation. With the original comb-line spacing of 115 MHz, overlaying spectra with gradually shifted comb lines we fully resolved amplitude and phase spectra of molecules with narrow Doppler-broadened lines, such as ν1+ν3 band of carbon disulfide (CS2) and its isotopologues. Also, we were able to observe the chemical oxidation reaction of CS2 by detecting traces of carbonyl sulfide (OCS) via its asymmetric ν3 stretch band.
