Gatti Davide, Sala Tommaso, Gotti Riccardo, Cocola Lorenzo, Poletto Luca, Prevedelli Marco, Laporta Paolo, Marangoni Marco
Dipartimento di Fisica - Politecnico di Milano and IFN-CNR, Piazza Leonardo da Vinci 32, 20133 Milano, Italy.
IFN-CNR-UOS Padova, Via Trasea 7, 35131 Padova, Italy.
J Chem Phys. 2015 Feb 21;142(7):074201. doi: 10.1063/1.4907939.
Extreme frequency accuracy and high sensitivity are obtained with a novel comb-locked cavity-ring-down spectrometer operating in the near-infrared from 1.5 to 1.63 μm. A key feature of our approach is the tight frequency locking of the probe laser to the comb, ensuring very high reproducibility and accuracy to the frequency axis upon scanning the comb repetition rate, as well as an efficient light injection into a length-swept high-finesse passive cavity containing the gas sample. Spectroscopic tests on the (30012) ← (00001) P14e line of CO2 at ∼1.57 μm demonstrate an accuracy of ∼17 kHz on the line center frequency in a Doppler broadening regime over the time scale of about 5 min, corresponding to four consecutive spectral scans of the absorption line. Over a single scan, which consists of 1500 spectral points over 75 s, the limit of detection is as low as 5.7 × 10(-11) cm(-1).
通过一种新型的梳状锁模腔衰荡光谱仪在1.5至1.63μm的近红外波段工作，可获得极高的频率精度和高灵敏度。我们方法的一个关键特性是探测激光与梳状光的紧密频率锁定，这确保了在扫描梳状重复率时频率轴具有非常高的可重复性和准确性，以及将光有效注入到包含气体样品的长度扫描高精细度无源腔中。在约1.57μm处对CO₂的(30012)←(00001) P14e线进行的光谱测试表明，在多普勒展宽 regime 下，约5分钟的时间尺度内，谱线中心频率的精度约为17kHz，这对应于吸收线的四次连续光谱扫描。在一次扫描中，该扫描在75秒内由1500个光谱点组成，检测限低至5.7×10⁻¹¹ cm⁻¹。 （注：“regime”这里可能是“区域、状态”等意思，结合语境不太明确准确含义，未准确翻译）
