Sampling Error Analysis of FTIR and Design of Low Noise Sampling System

In this paper, the sampling errors that can cause spectral noise of Fourier infrared spectrometer are introduced. The main reasons for the sampling errors are the position change of the interferometer moving mirror, the jitter in the motion process, the circuit delay and other random noise, etc. The Matlab is used to model and simulate, and the influence of these sampling errors on spectral noise is intuitively displayed. In order to reduce the sampling noise, an isochronous acquisition system through digital filter and oversampling is proposed. The sampling system does not require high precision for the driving structure of the moving mirror, and can reduce the time delay error caused by the analog filter circuit, simplify the structure and circuit design of the spectrometer, and improve the restoration quality of the infrared spectrum imaging.