Gap-variable Fabry-Perot interference type long-wave infrared dual mode spectral imaging system

Abstract

The invention provides a gap-variable Fabry-Perot interference type long-wave infrared dual mode spectral imaging system. The system includes a front-end imaging object lens, a gap-variable Fabry-Perot interferometer, a relay lens, a long-wave infrared detector and a signal processing system. The Fabry-Perot interferometer is constituted by a symmetrical wedge plate and a parallel flat slab, and an air gap of an interference cavity thus formed undergoes gradual change. The Fabry-Perot interferometer, compared with prior art interferometers, is advantaged by linear optical path and compact volume. The system is carried out in the following steps: when a carrying platform is in a staring state, through translating the interferometer in a direction perpendicular to an optical axis, acquiring the interference information of an object point at different phase positions within a field of view, conducting Fourier transform on the interference information to obtain spectral information of the object; when the carrying platform is in a push-scan mode, the interferometer is perpendicular to the optical axis in a symmetrical arrangement, the whole system conducting push-scan on an object scenery along with the carrying platform, and through rearrangement, acquiring the interference information of the object point at different phase positions within the field of view, conducting Fourier transform on the interference information to obtain the spectral information of the object.

Description

technical field [0001] The invention belongs to the field of spectral imaging, in particular to a variable-gap Fabry-Perot interference long-wave infrared dual-mode spectral imaging system. Background technique [0002] Interferometric spectral imaging technology obtains the interference light intensity information of the imaging target by adding an interferometer to the imaging system, and uses Fourier transform to restore the spectral data cube of the imaging target, which can achieve high luminous flux detection, thus having high spatial resolution and hyperspectral The advantages of resolution have great application potential in remote sensing imaging, resource exploration, environmental monitoring and other fields. In recent years, this kind of spectral imaging technology has been studied at home and abroad. According to the choice of interferometer, it is divided into Michelson interferometer, Sagnac interferometer, Mach-Zehnder interferometer and other spectral imagi...

AI Technical Summary

Problems solved by technology

The main disadvantages of this spectral imager are: firstly, under the condition of F#=5, the volume of the system is already relatively large. When the system needs two imaging objective lenses and a collimating objective lens, the volume of the instrument is limited by these objective lenses, and it is more difficult to realize miniaturization; secondly, a beam of light entering the Sagnac interferometer is reflected by three mirrors and split by a beam splitter. Light splitting through transmission, the system is not a linear optical path, the structural volume is difficult to be compact, and the slight displacement of the mirror and the beam splitter will affect the performance of the system; In the staring state, the system will not be able to obtain the interference information at different phases of the target point, that is, the spectral information of the target cannot be obtained

The main disadvantages of this spectral imager are: firstly, the system works in the visible and near-infrared bands, and cannot meet the detection requirements of targets with characteristic peaks in the long-wave infrared band, such as colorless poisonous gas; The air gap of the instrument is used to change the emitted wavelength value, so as to obtain the information of different target points in two-dimensional space at different wavelengths, so an accurate transmission mechanism is needed to control the air gap of the Fabry-Perot interferometer; in addition, When the carrying platform is in the push-broom working mode, while the system changes the air gap of the Fabry-Perot interferometer, the target in the field of view is also changing, and it is impossible to obtain the spectral information of the same target point at different wavelengths. , the system is only applicable to the staring work mode of the equipped platform

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