Design And Experiment Of Infrared Polarization Snapshot Spectral Imaging System

The spectral imaging system is an optical system that combines spectral analysis and imaging technology.The two-dimensional image information and one-dimensional spectral information of the target can be obtained simultaneously.It is widely used in environmental resource detection,meteorological observation and forecasting,land resource exploration and other fields.The infrared polarization snapshot spectral imaging system adds the functions of snapshot imaging and polarization detection based on the spectral imaging system.Snapshot imaging does not require time-sharing scanning,which improves imaging efficiency and system stability,and polarization detection improves the contrast between the target and the background.Since the polarization characteristics of an object are only related to its own material properties,the infrared polarization snapshot spectral imaging system has the advantages of high recognition rate and fast detection speed when detecting targets under weak radiation and complex background conditions.It is used in military camouflage recognition and natural disasters.It has broad application prospects in accident monitoring,space detection and other fields.This thesis carried out the theoretical research,optical system design,physical optics simulation,platform system construction and map detection experiment of infrared polarization snapshot spectral imaging system.The main research contents are as follows:（1）An infrared spectral imaging system combining polarization detection and snapshot imaging is proposed.The system consists of a static interference core composed of a roof-shaped stepped micromirror and a beam splitter.By introducing a polarizer array,the multi-channel polarization information of the target is simultaneously obtained,and the multi-channel interference information of the target is simultaneously obtained through the lens array to realize polarization snapshot imaging.The interference and imaging process of the system are analyzed,and the relationship between the parameters of the roof-shaped stepped micromirror and the spectral resolution of the system is given;the main source of stray light in the system is analyzed,and the method of suppressing stray light is given;The angular error of the polarizer,giving the error tolerance.（2）The optical design of the infrared polarization snapshot spectral imaging system is completed.Based on the system design indicators,the working band of the system,the size of the roof-shaped stepped micro-mirror,and the material and structure parameters of the wire grid polarizer array are determined;Aperture matching was carried out;optical aberration correction was realized through infrared optical material matching and optical binary surface design.The analysis results show that the transfer function of the rear imaging system is MTF>0.5@17lp/mm,and the distortion is less than 0.15%.The wave aberration RMS of the refraction-diffraction hybrid collimator lens is less thanλ/10.（3）The physical optics transmission process simulation of the infrared polarization snapshot spectral imaging system is completed.Optical simulation software was used to obtain a 16×16 polarization interferometric image array in non-sequential mode,and the spectral reconstruction of each Stokes vector was carried out to verify the polarization snapshot detection capability of the system map information.（4）The principle verification experiment of the infrared polarization snapshot spectral imaging system has been completed.The optical path of the polarization map detection system was built,the system polarization imaging experiment and map reconstruction algorithm research were carried out,the polarization interference image array of the target was obtained,and the spectral information was reconstructed.The Stokes vector image of the target is obtained by performing image calculation on the obtained polarization image,and the feature extraction of the target is realized through image fusion.The experimental results show that the spectral resolution of the system is 7.8cm^-1,and the Stokes vector measurement error is less than 5%.