Snapshot infrared Fourier transform imaging spectrometer for transient dynamic sensing

Imaging spectroscopy is an effective method for simultaneously acquiring the spatial information distribution and the spectral fingerprint characteristics of a target. Implementing dynamic target spectral mapping through optical scanning may lead to image artifacts and spectral interference. This paper proposes an innovative structure for a snapshot infrared Fourier transform Imaging spectrometer (SIFTIS), which utilizes a stepped micro-mirror and a lens array, combining the advantages of snapshot imaging spectroscopy and infrared spectral detection. The SIFTIS technology acquires a complete three-dimensional dataset within a single integration time, featuring good stability, strong real-time capability, and high spatiotemporal resolution. It has significant advantages in fields such as camouflage target recognition and harmful and pollutant gas measurement. Firstly, the optical field transmission model of SIFTIS was constructed, and the system's error propagation model was further deduced. The impact of the optical system and core optical components' aberration residues and positional errors on spectral mapping were analyzed, providing design error tolerance. Subsequently, preliminary experiments combined with simulation analysis were used to calibrate and correct the spectral shifts caused by rotation, pitch, and roll component errors of the stepped micro-mirrors reflective surfaces at various levels. Finally, imaging spectral detection of dynamic plume targets was conducted to demonstrate the desired results and feasibility.