A Spectral Restoration Correction Method Based on Polarization Interferometer

Abstract

The invention belongs to a polarization interference spectrum restoration correction method comprising the following steps of 1) preprocessing; the preprocessing includes interference signal sampling, noise reduction and phase correction; the points N of fast Fourier transform (FFT) are determined; and the wave number range v0-v1 is determined; 2) Fourier transform: the interference signals obtained through preprocessing are calculated by using the FFT algorithm; 3) correction; and 4) coordinate transform. According to the polarization interference spectrum restoration correction method, the wave number obtained through FFT can be fast and effectively compensated one by one by using the mode of software algorithm by only determining the material properties of a phase compensator.

Description

technical field [0001] The invention relates to the field of Fourier transform spectrum restoration, in particular to a spectrum restoration correction method based on a polarization interferometer. Background technique [0002] For the classic Michelson interferometric spectrometer, the change of the optical path difference at any wavelength during the scanning of the moving mirror is theoretically consistent. The phase change of the cosine interference curve at any wavelength mainly depends on the wave number and the scanning amount, and the ratio of the modulation frequencies of different wavelengths is equal to the ratio of the wave number. Therefore, for polychromatic light, the spectral curve can be accurately restored by performing fast Fourier transform (FFT) directly. For some nonlinear interference signals such as elastic optical modulation interference, the phase change has a nonlinear relationship with the scanning amount, and the Fourier transform is only appli...

AI Technical Summary

Problems solved by technology

First of all, for a single wavelength, the phase change and the scanning amount are linear, which is consistent with the classical Michelson interference, so the NUFFT algorithm cannot be used; secondly, the ratio of the modulation frequency of different wavelengths depends on the wave number and birefringence The product of the rate difference, so FFT cannot be used directly, otherwise it will cause serious spectral distortion

In summary, for polarization interference spectroscopy, neither traditional FFT nor NUFFT can accurately restore the spectrum

Images