The Technique Of Hyperspectral Polarization Imaging Based On Acousto-optic Tunable Filter And Liquid Crystal Variable Retarder

Spectropolarimetric imaging is a new technology that obtaining the information on space,polarization and spectrum simultaneously,the comprehensive utilization of multi-dimensional information can be further to improve the ability of target recognition detection.Therefore,the spectropolarimetric imaging technology has been used in fields of military detection,medical detection and environment detection,etc.In this paper,the factors that affect the system measurement accuracy of spectrum and polarization are analyzed theoretically and corrected experimently based on the AOTF and LCVR.In addition,a fast measurement method of Stokes parameters has been proposed in this paper.Therefore,we must solve these problems that how to make the system can achieve high quality and high precision target detection before it is applied to practice.Firstly,the principles and fundamental performance parameters of AOTF and LCVR were studied.According to the working principle of AOTF,the spectral resolution and spectral broadening were analyzed from the perspective of ultrasonic diffraction.In addition,the reason that different angle of incident light lead to wavelength change of diffraction light is analyzed theoretically,which would provide a theoretical basis about spectral-correction and spectral measurement of high precision.Secondly,a new Spectropolarimetric imaging system is proposed based on the AOTF and double LCVRs.On the foundation of the polarization of light and the Mueller matrix of optical element,the Spectropolarimetric measurement model of this system is established,and the highly efficient measurement method based on Stokes parameters is put forward for the first time.Thirdly,We studied the change of diffraction light when the incident light vertical incidence and non-normal incidence AOTF,and the correction equation of spectrum is obtained by least square method.The purpose is that the system is designed to realize the spectral measurement of high precision.We also studied the calibration method of initial phase delay about LCVR,in order to realize the polarization measurement of high precision.Finally,A hyper-spectral full-polarization imaging prototypes(visible)is designed to complete.The method of spectral measurement and Stokes-parameter measurement are verified experimentally via the prototype.Besides,the prototype is tested in field in order to verify its feasibility and practicability.