Research on laboratory spectral calibration method of two-dimensional spatial heterodyne spectrometer

摘要

Spatial heterodyne spectroscopy has the characteristics of hyperspectral resolution, no moving parts and high light flux. It can be used in many fields such as atmospheric composition and physical parameters measurement, astronomical observation and Raman spectrum detection. The limited number of detector pixels in traditional spatial heterodyne spectrometer can only measure a small range near the selected frequency of Littrow wavenumber, while the echelle gratings were used instead of the diffraction gratings, and the grating were rotated at an appropriate angle to separate the spatial dimension of the interferogram of the plane array, i.e. two-dimensional spatial heterodyne spectroscopy. On the premise of not reducing spectral resolution, the detection spectral range was greatly broadened. The spectral calibration method was studied for the experimental device of two-dimensional spatial heterodyne spectrometer. Firstly, the processing flow from the measured interferogram to the restored spectrum was given, and the flat field, apodization and zero filling methods of two-dimensional data were mainly introduced. According to the principle of two-dimensional interference, single- order spectral resolution, effective spectral range and multi-order calibration method are determined. Spectral calibration verification experiments were carried out on the experimental device by using Hg hollow cathode lamp in the laboratory, and the results of spectral calibration were given.