Physics Department of Politecnico di Milano and IFN-CNR, Via G. Previati 1/C, 23900, Lecco, Italy.
King Abdullah University of Science and Technology (KAUST), Clean Combustion Research Center (CCRC), Thuwal, 23955, Saudi Arabia.
Sci Rep. 2018 Jan 22;8(1):1292. doi: 10.1038/s41598-018-19188-2.
We report for the first time the frequency locking of an extended-cavity quantum-cascade-laser (EC-QCL) to a near-infrared frequency comb. The locked laser source is exploited to carry out molecular spectroscopy around 7.8 μm with a line-centre frequency combined uncertainty of ~63 kHz. The strength of the approach, in view of an accurate retrieval of line centre frequencies over a spectral range as large as 100 cm, is demonstrated on the P(40), P(18) and R(31) lines of the fundamental rovibrational band of NO covering the centre and edges of the P and R branches. The spectrometer has the potential to be straightforwardly extended to other spectral ranges, till 12 μm, which is the current wavelength limit for commercial cw EC-QCLs.
我们首次报告了扩展腔量子级联激光器（EC-QCL）到近红外频率梳的频率锁定。锁定后的激光源被用于在 7.8μm 附近进行分子光谱学测量，其线中心频率组合不确定度约为 63kHz。该方法的优势在于，即使在 100cm 这样大的光谱范围内，也可以精确地检索线中心频率，我们在 NO 的基频转动-振动带的 P(40)、P(18)和 R(31)线中验证了这一点，这些谱线覆盖了 P 和 R 支的中心和边缘。该光谱仪有可能直接扩展到其他光谱范围，直到 12μm，这是当前商用连续波 EC-QCL 的波长极限。
