Research On The Key Control Technology In The Spectrum Full-polarization Imaging System

The subject of spectrum full-polarization imaging is a new four-dimensional signal acquisition technology,which combines spectrum with full-polarization and image detection,has a increasingly important application potential in the fields of space exploration,remote sensing,medical study,environmental science and chemical analysis and so on.In this paper,we used the Acousto-optic Tunable Filter(AOTF)as the filter device,the Liquid Crystal Variable Retarder(LCVR)as the polarization modulation device,and then proposed a spectral full-polarization imaging detection system,took on researches focus on the key control technologies of the system.Based on the theory of polarization state of light,the filter principle of AOTF and the phase delay principle of LCVR,the spectrum full-polarization imaging system combine AOTF with double LCVRs is designed.Firstly,a new method to detect polarization is presented for the spectral polarization imaging system,and the new method to obtain the full-Stokes vector is derived in detail,in which the two LCVRs are controlled by the two outputs of the same polarization driving controller,the full-Stokes parameters can be obtained with four groups of phase delay which are plunging same.Secondly,a dual-LCVRs driver controller is designed,which can output two voltages simultaneously and steadily,and a computer programming is completed by LabVIEW,which can realize the joint debugging of the controller.Thirdly,according to the study of auto-focusing technology in the spectral polarization imaging system,and using the improved hill-climbing search algorithm which combined with the ergodic-search algorithm,a auto-focusing controller is designed.Finally,we established the experimental prototype,and carried out experiments of the polarization detection controller,the auto-focusing controller and the spectral full-polarization imaging to verify the practicability of the design.The new method of full-Stokes vector polarization detection proposed in this paper obtaining a simple algorithm,the full-polarization detection controller performs satisfactorily,the auto-focusing controller can effectively improve the clarity of the images.Briefly,the spectrum full-polarization imaging system which combined AOTF with dual-LCVRs can provide theoretical and experimental reference for spectral polarization imaging technology.