论文标题
高速傅立叶转变红外光谱与相对延迟线
High-speed Fourier-transform infrared spectroscopy with phase-controlled delay line
论文作者
论文摘要
傅立叶转换红外光谱（FTIR）是通过光学编码的振动特征的中红外（MIR）分子光谱分析的黄金标准。迈克尔逊型FTIR和miR双弯曲光谱仪使我们能够通过宽带和高分辨率光谱功能同时研究多个分子物种。但是，由于较低的时间分辨率，这些分辨率从根本上受到信噪比（SNR）的限制，因此这些不适用于高速测量。在这项研究中，我们开发了一种称为相控制的傅立叶转换红外光谱（PC-FTR）的高速FTIR光谱技术，该光谱（PC-FTRIR）具有以10 kHz速率测量miR吸收光谱的能力。 PC-FTIR通过任意调整仪器光谱分辨率，在各种光谱带宽上以高SNR的高扫描速率证明了高扫描速率。作为原理演示的证明，我们以24 kHz的速度测量了两种液体的高速混合动力学。我们还测量具有较高光谱分辨率的气相分子的miR光谱，速率为12 kHz。该高速miR光谱仪对于测量非重复的快速现象并在短时间内获取大量光谱数据可能特别有用。
Fourier-transform infrared spectroscopy (FTIR) is the golden standard of mid-infrared (MIR) molecular spectroscopic analysis through optically-encoded vibrational signatures. Michelson-type FTIR and MIR dual-comb spectrometers allow us to simultaneously investigate multiple molecular species via the broadband and high-resolution spectroscopic capabilities. However, these are not applicable to high-speed measurements due to the low temporal resolution which is fundamentally limited by the signal-to-noise ratio (SNR). In this study, we develop a high-speed FTIR spectroscopy technique called phase-controlled Fourier-transform infrared spectroscopy (PC-FTIR) that has the capability to measure MIR absorption spectra at a rate of above 10 kHz. PC-FTIR demonstrates the high scan rate with a high SNR for various spectral bandwidths by arbitrarily adjusting the instrumental spectral resolution. As a proof of principle demonstration, we measure high-speed mixing dynamics of two liquids at a rate of 24 kHz. We also measure MIR spectra of gas-phase molecules with higher spectral resolution at a rate of 12 kHz. This high-speed MIR spectrometer could be especially useful for measuring non-repetitive fast phenomena and acquiring a large amount spectral data within a short time.
