An oversampling software-triggering interferogram method for Fourier-transform infrared spectrometers

• DOI: 10.1016/j.infrared.2021.103805
• Publication Date: 2021-06-10T08:21:50Z
• Authors: Xiangyun Ma; Jinglai Sun; Yangguang Han; Yunpeng Yang; Qifeng Li; Huijie Wang
• Keywords: 0103 physical sciences; 01 natural sciences

Abstract Fourier-transform spectrometers (FTSs) are widely used for spectroscopic analysis in various fields. Hardware-triggering interferogram sampling is commonly used in commercial FTSs, which performs interferogram acquisition at equal increments of optical path difference (OPD). However, due to the OPD of FTSs over time is non-uniform, the stability of hardware-triggering sampling method strongly suffers from the variation of sampling frequency in the time domain. In this paper, we propose an oversampling software-triggering interferogram method based on the OPD iterative algorithm and the non-uniform discrete Fourier transform (NUDFT). The non-uniform OPD variable can be accurately calculated, which is significant to spectral recovery using the NUDFT. This oversampling method has been effectively adopted in our home-made near-infrared FTS, which features a rotating interferometer. Moreover, it is found that the spectral signal-to-noise ratio (SNR) can be increased by ~ 5.3 times, benefitting from the oversampling software-triggering interferogram acquisition. Published by AIP Publishing.