Method for enhancing broadband interference spectral resolution and spectrograph

Abstract

The invention discloses a method for enhancing the broadband interference spectral resolution and a spectrograph. The method for enhancing the broadband interference spectral resolution comprises the steps that after dispersion is conducted on a broadband spectrum, continuous monochromatic spectrums are obtained; interference measurement is conducted on the monochromatic spectrums, so that monochromatic spectrum interferograms are obtained; resolution enhancement is conducted on each monochromatic spectrum interferogram so that the spectral resolution for spectrum reconstruction of each monochromatic spectrum interferogram can be improved. The broadband spectrum is changed into a series of narrowband spectrums, so that the interferogram modulation degree of each narrowband spectrum is improved; on the basis of the maximum optical path difference, the optimal path difference is further increased through the method for enhancing the interference spectral resolution, and therefore the spectrum with a higher resolution is obtained.

Description

technical field [0001] The invention relates to the technical field of optical imaging, in particular to a wide-band interference spectrum resolution enhancement method and a spectrometer. Background technique [0002] As an important means of modern spectral analysis technology, Fourier transform spectroscopy (also known as interference spectroscopy) is a research focus in the field of spectral technology. At present, the application of this technology is very wide, especially in the field of atmospheric remote sensing. Its high precision, high sensitivity, high spectral resolution and other advantages have become the preferred technology for atmospheric composition detection. The core of FTS (Fourier Transform Spectrometer, Fourier Transform Spectrometer) is an interferometer, which was proposed by Michelson in the 1880s, including beam splitters, stationary mirrors, and moving mirrors, which together with the pre-mirror and Fourier mirror constitute a traditional Michels...

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Problems solved by technology

[0004] The resolution of spectrum obtained by Michelson interferometric spectrometer is determined by the maximum optical path difference between the moving mirror and the stationary mirror. The maximum optical path difference is determined by the maximum distance obtained by moving the linear moving mirror. Restricted by factors such as technology, the maximum distance obtained by moving the linear motion mirror is usually limited within a certain range, which also limits the highest spectral resolution that can be achieved by Michelson interferometric spectrometers

[0005] In the process of broadband spectral detection, the interference data value (modulation degree) of the Michelson interferometric spectrometer decreases sharply with the increase of the optical path difference. noise reduction

[0006] In order to improve the stability and repeatability of the Michelson interferometric spectrometer, various forms of interferometric spectrometer schemes have emerged, such as using rotating mirrors instead of linear motion mirrors to improve stability and repeatability, but the maximum optical path difference that can be achieved reduced, thereby reducing the spectral resolution

In order to improve the spectral resolution, the interference spectral resolution enhancement method is proposed abroad, but this method is only suitable for monochromatic spectrum or narrow-band spectrum, and has almost no effect for wide-band spectrum.

In addition, in order to reduce the influence of noise on the interferogram at the wide-band spectrum and long optical path difference, foreign countries have proposed to improve the signal-to-noise ratio through digital filtering, but it will lead to the reduction of spectral resolution and spectral distortion.

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