物理学报Issue(14)：1-8,8.DOI:10.7498/aps.64.140702
基于声光滤光和液晶相位调谐的高光谱全偏振成像新技术∗
A new technique of full p olarization hyp ersp ectral imaging based on acousto-optic tunable filter and liquid crystal variable retarder
摘要
Abstract
In order to achieve all Stokes parameters of spectral image with high spectral resolution, high spatial resolution, high polarization accuracy, high signal-to-noise ratio and good stability, taking into account the orthogonal characteristic of ±1 order diffraction light which diffracts from a acousto-optic tunable filter (AOTF), a new technique of full polarization hyperspectral imaging is presented. It uses one AOTF to diffract the incident light, one liquid crystal variable retarder (LCVR) to modulate the light retardation, and two CCDs to image the ±1 order diffraction light, respectively. According to the Muller matrixes of all optical elements in the system, the basic working principle of the new technique is that LCVR sequentially provides the retardation 2π, 1.5π,πand 0.5πfor each spectral channel, so the CCD obtains corresponding images. After analyzing these images, the all Stokes parameters are obtained;the precision of this system for polarization imaging is determined mainly by polarization modulation device LCVR. Considering the azimuth of LCVR fast axis and retardation precision at the same time, it is unveiled that LCVR has no effect on the accuracy of the first Stokes parameter, and the relative errors of other latter 3 Stokes parameters are less than 0.064%, 0.31% and 3.97%; then, our prototype system is used to do the outdoor experiments in a summer sunny morning, images data for 26 spectral channels with spectral bandwidth of 10 nm, which are from 450 nm to 700 nm, are acquired, the imaging quality is very fine. Firstly, LCVR are not assembled in our prototype system, and AOTF works in the sweeping frequency mode. The spectrum from each CCD proves that the diffraction efficiency of AOTF ±1 order diffraction light is not completely the same, and the difference must be considered in polarized image processing. Then another experiment is done after LCVR has been assembled. The image data of the incident light of 600 nm are taken for example to discuss its all Stokes parameters in detail. The results show that the principle of the new technique is correct and the new scheme is feasible. This study provides a new theory and implementation scheme for the polarization spectral imaging technology.关键词
光谱/偏振/Stokes参量Key words
spectrum/polarization/Stokes parameters引用本文复制引用
李克武,王志斌,杨常青,张瑞,王耀利,宋雁鹏..基于声光滤光和液晶相位调谐的高光谱全偏振成像新技术∗[J].物理学报,2015,(14):1-8,8.基金项目
国家国际科技合作专项项目(批准号:2013DFR1015)和国家自然科学基金(批准号:61127015)资助的课题.@@@@* Project supported by the International Science and Technology Cooperation Special, China (Grant No.2013DFR1015), and the National Natural Science Foundation of China (Grant Nos.61127015) （批准号:2013DFR1015）
