论文标题
高分辨率量子级联激光激光双弯曲光谱在中红外具有绝对频率参考
High-Resolution Quantum Cascade Laser Dual-Comb Spectroscopy in the Mid-Infrared with Absolute Frequency Referencing
论文作者
论文摘要
量子级联激光器（QCL）频率梳子通过其高亮度和快速的时间分辨率彻底改变了中红外（miR）光谱，并且是一种完全集成且具有成本效益的传感器的有希望的技术。至于其他集成的梳子源，例如微型剂量和频带间级联激光器，QCLs具有几个GHz的梳子间距，这足以测量广泛的吸收结构，通常在液体或固体样品中发现。但是，高分辨率的气相光谱需要光谱交织和频率校准。我们开发了一种频率校准方案，用于使用具有多GHz间距的梳子快速交织的测量。然后，我们在40 cm $^{ - 1} $上使用两个QCLS以7.8 $ \MATHRMμ$ m的速度进行了600 kHz精度的双弯曲光谱。这项工作是对MIR中复杂分子混合物快速指纹的重要贡献。此外，校准方案可与微型汤一起用于光谱和范围，包括在梳状和梳理的设置中。
Quantum cascade laser (QCL) frequency combs have revolutionized mid-infrared (MIR) spectroscopy by their high brightness and fast temporal resolution, and are a promising technology for fully-integrated and cost-effective sensors. As for other integrated comb sources such as micro-combs and interband cascade laser, QCLs have a comb spacing of several GHz, which is adequate for measurements of wide absorbing structures, typically found in liquid or solid samples. However, high-resolution gas-phase spectra require spectral interleaving and frequency calibration. We developed a frequency calibration scheme for fast interleaved measurements with combs featuring multi-GHz spacing. We then demonstrate dual-comb spectroscopy with 600 kHz accuracy in single-shot 54-ms measurements over 40 cm$^{-1}$ using two QCLs at 7.8 $\mathrmμ$m. This work is an important contribution towards fast fingerprinting of complex molecular mixtures in the MIR. Moreover, the calibration scheme could be used with micro-combs for spectroscopy and ranging, both in comb-swept and comb-calibrated setups.
