Dual-channel Fourier spectrograph and detection method

Abstract

The present invention discloses a dual-channel Fourier spectrograph and a detection method. The dual-channel Fourier spectrograph includes a collimating objective lens, a dual-channel interferometer, a first detection module, a second detection module and a data processing system which are all arranged sequentially along the direction of an optical path; the first detection module and the second detection module are both connected with the data processing system; the dual-channel interferometer comprises a beam splitter, a first prism, a first reflector, a second reflector and a second prism which share one optical axis and are arranged sequentially clockwise; a 45-degree angle is formed between the beam splitter and an incoming optical axis; the first reflector and the second reflector are parallel to the beam splitter; and the first prism can rotate or swing around an axis of which the prism center is perpendicular to a paper surface. With the dual-channel Fourier spectrograph and the detection method adopted, two paths of interference information of a light beam emitted from a detection point (a target) can be obtained simultaneously, the amount of the change of the light intensity of the detection point with time can be demodulated out from the interference information, and therefore, influence on the interference information caused by the change of the light intensity of the detection point can be effectively eliminated, and the accurate spectral information of the detection point can be restored.

Description

technical field [0001] The invention relates to the field of spectral detection, in particular to a dual-channel Fourier spectrometer and a detection method, which can perform spectral detection on a light intensity transformation target. Background technique [0002] The Fourier spectrometer uses the Fourier transform to invert the spectral information of the target by detecting the interference signal of the target. Compared with traditional dispersive spectrometers, it has the advantages of high luminous flux and multiple channels, and is suitable for detecting broad spectrum spectrum, especially infrared spectrum information. Fourier spectrometers have become important detection instruments in the fields of astronomical observation, space remote sensing, atmospheric detection, elemental analysis, pollution monitoring, and biomedicine. [0003] The existing Fourier spectrometers are mainly divided into two categories, one is the time modulation type, which uses a transla...

AI Technical Summary

Problems solved by technology

However, there are two problems with this type of data processing algorithm. One is that the approximate fitting process can only approximate the change in light intensity of the detection point over time, which is not accurate; the other is that when the light intensity of the detection point fluctuates slightly (For example, when detecting aircraft exhaust or detecting the spectrum of outdoor polluted gases), it is impossible to effectively obtain the change of light intensity at the detection point over time, which leads to large errors in the restored spectrum

[0004] Using the existing time-modulated Fourier spectrometer for detection, the data processing algorithm cannot effectively eliminate the background intensity, resulting in large errors in the restored spectrum

Using the existing spatial modulation Fourier spectrometer for detection, due to the use of spatial spectroscopy technology, the signal-to-noise ratio of the system is lower than that of the time modulation Fourier spectrometer, which affects the accuracy of the restored spectrum

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