Insero G, Borri S, Calonico D, Pastor P Cancio, Clivati C, D'Ambrosio D, De Natale P, Inguscio M, Levi F, Santambrogio G
Istituto Nazionale di Ottica-CNR & Dipartimento di Fisica e Astronomia, Università di Firenze & European Laboratory for Non-Linear Spectroscopy LENS, Via Nello Carrara 1, 50019, Sesto Fiorentino, Italy.
INFN, Istituto Nazionale di Fisica Nucleare, Sez. di Firenze, Via Nello Carrara 1, 50019, Sesto Fiorentino, Italy.
Sci Rep. 2017 Oct 6;7(1):12780. doi: 10.1038/s41598-017-12891-6.
High-resolution spectroscopy in the 1-10 μm region has never been fully tackled for the lack of widely-tunable and practical light sources. Indeed, all solutions proposed thus far suffer from at least one of three issues: they are feasible only in a narrow spectral range; the power available for spectroscopy is limited; the frequency accuracy is poor. Here, we present a setup for high-resolution spectroscopy, whose approach can be applied in the whole 1-10 μm range. It combines the power of quantum cascade lasers (QCLs) and the accuracy achievable by difference frequency generation using an orientation patterned GaP crystal. The frequency is measured against a primary frequency standard using the Italian metrological fibre link network. We demonstrate the performance of the setup by measuring a vibrational transition in a highly-excited metastable state of CO around 6 μm with 11 digits of precision.
由于缺乏广泛可调谐且实用的光源，1-10微米区域的高分辨率光谱学从未得到充分解决。事实上，迄今为止提出的所有解决方案都至少存在以下三个问题之一：它们仅在狭窄的光谱范围内可行；可用于光谱学的功率有限；频率精度较差。在此，我们展示了一种用于高分辨率光谱学的装置，其方法可应用于整个1-10微米范围。它结合了量子级联激光器（QCL）的功率以及使用取向图案化GaP晶体通过差频产生可实现的精度。使用意大利计量光纤链路网络根据一级频率标准测量频率。我们通过以11位精度测量6微米附近CO高激发亚稳态的振动跃迁来证明该装置的性能。
