Interferogram combination from stepped interferometry in a static modulated Fourier-transform spectrometer for enhanced selective performance

Static-modulated Fourier-transform spectroscopic techniques have attracted attention due to their relative advantages over conventional Fourier transform spectrometer, including faster measurement, compact structure, and strong immunity to vibrations. However, limitations such as lower spectral resolution and reduced signal-to-noise ratio (SNR) remain key challenges. In a static-modulated Fourier transform spectrometer, shorter mirror displacements degrade spectral resolution, while longer displacements result in poor SNR. To address this trade-off, we propose an approach that enhances both spectral resolution and SNR by combining interferograms obtained through stepped interferometry in a static-modulated Fourier transform spectrometer. The employed light source has a spectral width of 370cm⁻¹ centered at 6451cm⁻¹. The proposed algorithm achieves an effective spectral resolution of 48.8cm⁻¹ and an SNR of 118.4— an 18% improvement. These results demonstrate that the inherent trade-off between spectral resolution and SNR in static-modulated Fourier-transform spectrometers can be mitigated through the proposed method.