Study On Polarization Imaging Technology And System Of Medium-wave Infrared Spectropolarimetric Imaging Technology

The spectropolarimetric imaging technique is a new optical detection technology which integrates spectral measurement technology and polarization imaging technology.It can not only obtain the spectral information of the target,but also obtain the image information and polarization information,which provides a powerful guarantee for the accurate recognition of the target.At present,the spectropolarimetric imaging technique is widely used in biomedical diagnosis,target detection and recognition,space remote sensing,environmental monitoring and other fields.In order to accurately understand the working principle of the spectropolarimetric imaging system and study the new type of the spectropolarimetric imaging system,in this paper,the spectral measurement technique and polarization imaging technique of spectropolarimetric imaging technique based on spectral measurement system and simultaneous polarization imaging system with division of aperure are studied.On the basis of those,a spectropolarimetric imaging system in medium-wave infrared is constructed.Based on the traditional Michelson system,the medium-wave infrared spectropolarimetric imaging system realizes the measurement of polarization information and the static interference system by introducing polarization modulation module and multistage step micro-mirror.Compared with the traditional Fourier transform imaging spectrometer,the system has the advantages of high throughput and multi-channel,but also has the advantage of large amount of information.The work of this paper includes three parts:1.The research of spectral measurement technology: A spatial modulation Fourier Transform micro-spectrometer based on micro-optical elements.The infrared microstructure diffractive optical elements,multi-step micro-mirrors and microlens array are introduced to realize the miniaturization of the instrument.In addition,The structure and basic principle of Fourier Transform Infrared micro-spectrometer are introduced.The design theory of micro-collimation system is analized based on the negative dispersion,the abberation correction and the arbitrary phase modulation characteristics of diffractive optical element.Combined with the characteristics of micro-static interference system,the micro-focusing coupled optical system is analyzed and designed.Based on the wave aberration theory and the Sellmeier dispersion formula,the influence of residual aberration on spectral recovery is studied,as well as the diffraction efficiency of diffraction surface in single-chip hybrid diffractiverefractive collimating lens.The effects of diffraction of multi-stage micro-mirrors and the aperture diffraction of microlens array on spectral recovery are studied by using the scalar diffraction theory.Furthermore,the influence of axial assembly error of relay system on the whole system performance is studied.Finally,in order to verify the accuracy of the system design results,the optical simulation software ASAP is used to simulate the infrared micro-Fourier transform spectrometer.2.The research of polarization imaging technology: Based on aperture division and polarization-detection technology,A novel medium-wave infrared aperturedivision simultaneous polarization-imaging system is proposed.Equal weight variance was used to optimize the polarization axis direction of the linear polarizer and the fastaxis azimuth angle of the wave plate in each channel to reduce the impact of the random intensity fluctuations in the infrared detector.A calibration method of the system is proposed by investigating Fourier analysis method of a rotatable retarder fixed polarizer Stokes polarimeter,which is used to improve the accuracy of polarization measurement.The calibration theory of the system is deduced.The integration and calibration of this system is carried out,and the polarization imaging experiment is carried out using the calibrated system.Finally,the image fusion about the obtained image is done.3.The research of spectropolarimetric imaging technology: A novel polarization interference imaging system based on micro-static interference system is proposed.The parameter calculation of the system is completed.According to the theory of paraxial optics,the design scheme of the objective lens and relay system is studied to match well about them and reduce energy loss.When the incident light is completely non polarized and polarized,the transmission rate of the system is analyzed,and the minimum weak radiation detected by the system is given.Finally,the influence of the Polarizer's rotation error on the polarization measurement is analyzed.The tolerance of polarizer is given in order to satisfy the polarization detection accuracy of 2%,which provides the guidance for actual assembly.