光谱成像技术研究室知识库

In the process of wide-band spectrum detection, interferogram acquisition of the traditional Michelson interferometer needs to follow Nyquist sampling theorem, the static performance such as high resolution of moving mirror scanning and the dynamic performance such as transient response need to meet strict requirements, which usually make the spectrometer system structure complex. Meanwhile, the interference modulation efficiency of traditional Michelson interferometer will drop sharply with the increase of optical path difference(OPD). In this way, the interference data value at the long optical path difference will be submerged by noise, which will reduce the signal-to-noise ratio of reconstructed spectrum. In order to simultaneously achieve spectrum detection with wide-band spectrum, high resolution and high signal-to-noise ratio, this paper introduces a configuration of wide-band interference spectrometer based on band-pass sampling technology. The wide-band interference spectrometer includes dispersion unit and interference modulation unit. Firstly, the dispersion unit pre-disperses the wide spectrum into continuous spectrum distributed along wavelength and divides the interference modulation signal of continuous spectrum into several interference signals of narrow-band spectrum. Secondly, the interference modulation unit carries out interference modulation on the dispersed continuous spectrum and the interferograms of every narrow-band spectrum are sampled and obtain the interferogram sequence of every narrow-band spectrum according to the band-pass sampling theorem. Finally, the spectral distribution of the detection target can be obtained by data processing and spectral superposition. The interference spectrometer provides a new idea for the development of spectral detection with wide spectral range, high resolution and high signalto- noise ratio. © 2020 SPIE.