摘要
本文介绍了一种基于Wollaston棱镜角剪切和Savart偏光镜横向剪切组合的静态、紧凑型、高通量差分偏振干涉成像光谱技术.其显著特点是无运动部件,可同时获取目标正交偏振组分的干涉图和二维空间图像.干涉图经傅里叶变换和图像融合算法可得到正交偏振组分的偏振光谱图像,正交偏振光谱图像之和等效于传统强度光谱图像,正交偏振光谱图像之差称为差分偏振光谱图像.高对比度的差分偏振光谱不仅能刻画目标详细的表面形貌、纹理和结构信息,还可反演弹性散射粒子的尺度、浓度和折射率等信息.文中描述了差分偏振干涉成像光谱仪的原理结构,给出了干涉强度分布规律表达式,分析了完整干涉图和二维空间图像的数据获取模式.利用杨氏干涉模型对光通过Savart偏光镜后形成干涉直条纹的近轴关系进行了深入分析.利用光场衍射理论确定了光谱仪中准直透镜和成像透镜实现紧凑化的结构关系.计算机仿真模拟验证了方案的可行性.为偏振成像光谱仪的发展提供了一种新思路.
A static, compact, high optical throughput polarization-difference iaterference imaging spectrometer is presented. It is based on the combination of the angular shear of Wollaston prism and the lateral shear of Savart polariscope. Its remarkable characteristic is the simultaneous acquisition of the interferograms and two-dimensional images for the orthogonal polarization components of targets. Polarization spectral images of the components can be reconstructed using the algorithms of Fourier transformation and image fusion. A summation of the orthogonal polarization spectral images is equivalent to that of the conventional intensity spectral image. The difference is that the orthogonal polarization spectral images is named as polarization-difference spectral image. A higher contrast of the polarization-difference spectral image can not only provide more detailed texture information for the targets, but also can derive the size, concentration, and refractive index of elastic-scattered particles. The principle of polarization-difference interference imaging spectrometer is demonstrated in this paper. Expressions for interference intensities and theoretical simulation are presented. The mode for acquiring data is described. Approximate paraxial conditions of Fourier imaging lens for the formation of straight fringes are analyzed by using the Young＇s interference mode; and the influence factors for the visibility of fringes are analyzed. For the realization of a more compact system, the relationship between the collimating lens and imaging lens is analyzed in terms of optical field diffraction theory. The feasibility of the system is demonstrated by numerical simulation. This research can provide a novel development strategy for imaging spectropolarimeter.
出处
《物理学报》
SCIE
EI
CAS
CSCD
北大核心
2014年第11期143-153,共11页
Acta Physica Sinica
基金
高等学校博士学科点专项科研基金(新教师类)(批准号:20130201120047)
中央高校基本科研业务费专项资金(批准号:xjj2013044)
国家自然科学基金(批准号:61275184)
国家高技术研究发展计划(批准号:2012AA120211)
陕西省自然科学基础研究计划(批准号:2014JQ8362)
西安交通大学新教师科研支持计划资助的课题~~
关键词
成像光谱仪
干涉
偏振
双折射元件
imaging spectrometer, interference, polarization, birefringent component
