Design of hyper-spectral and full-polarization imager based on AOTF and LCVR

Abstract

With the development of spectral imaging technology and polarization imaging technology, capturing the spectral profile and polarization signatures simultaneously will provide a wealth of evidence which helps to recognize the objects. Thus it has become a new trend in the area of remote sensing technology. In this paper, the existing polarization spectral imaging technologies are introduced and compared a new designing scheme to realize the miniaturized hyper-spectral and full-polarization imager are proposed, which is based on the combination of Acousto-Optic Tunable Filter (AOTF) and Liquid Crystal Variable Retarder (LCVR). The designing scheme is mainly composed of three modules: the spectral splitting module based on AOTF, the polarization control module based on LCVR and the image acquisition module based on Charge Coupled Device (CCD). The use of AOTF assists in achieving a hyper-spectral resolution higher than 5nm, as well as the abundant spectral information. While the LCVR enables us to gain multiple sets of polarization images of the target, after that, the polarization state of the target can be extracted according to Stokes vector and Mueller matrix. This designing scheme ensures a wide spectral range from 400nm to 2400nm by means of electronic tuning, and also achieves the hyper-spectral and full-polarization images of the target in rapid succession without mechanical moving parts. Besides, the development, testing, calibration and test scheme of the system are also introduced in the rest of the paper.