1 长春理工大学光电工程学院，吉林 长春 130022
2 长春理工大学空间光电技术吉林省重点实验室，吉林 长春 130022
为了表征典型卫星表面材料的近红外偏振特性，基于微面元模型并综合考虑镜面散射及漫散射来描述目标表面的反射特性，引入镜面系数及漫反射率来明确两种反射对偏振度的影响，并考虑实际粗糙材料表面存在的遮蔽效应，建立一种更完善的多参量偏振双向反射分布函数模型，进而推导出适用于粗糙材料表面的光学反射偏振度表达式。对典型卫星表面材料进行近红外偏振实验，采用遗传算法从实验数据中反演卫星表面材料的多参量数值，进而得到偏振信息仿真曲线。结果表明，该多参量偏振双向反射分布函数的仿真值与实验测试值能够较好的吻合，不同卫星表面材料的近红外偏振特性有较大分布差异。
散射 双向反射分布函数 散射偏振 近红外反射偏振特性 偏振度 激光与光电子学进展
2021, 58(19): 1929001
1 桂林电子科技大学 电子工程与自动化学院, 广西 桂林 541004
2 桂林电子科技大学 广西光电信息处理重点实验室, 广西 桂林 541004
为表征物体表面偏振散射特性对目标偏振信息提取的影响, 基于微面元散射模型结合Kubel-Munk理论, 综合考虑镜面散射和漫散射, 构建一种改进的偏振双向反射分布函数(pBRDF)模型, 得到物体表面散射光的偏振度与材料复折射率、方位角、探测角和入射波长等因素的数学模型, 并利用该模型对基础材料的复折射率进行反演.结合实际应用利用FD-1665偏振成像仪在不同影响因子条件下对目标表面进行了一系列偏振探测实验.最后将数值模拟结果和实测数据进行比较, 其材料偏振特性曲线与实测数据吻合, 表明修正后的模型有较高的精确度, 该模型可以为后续的偏振监测和目标识别工作提供理论支持.
偏振 双向反射分布函数 散射偏振 偏振成像 偏振探测 Polarization characteristics Polarization bi-directional distribution function Scattering polarization Polarization imaging Polarization detection
1 中国科学技术大学环境科学与光电技术学院, 安徽 合肥 230026
2 中国科学院安徽光学精密机械研究所通用光学定标与表征技术重点实验室, 安徽 合肥 230031
为了表征涂层的表面散射偏振特性,基于Kubelka-Munk理论,综合考虑表面散射和体散射,建立了一种多参量偏振双向反射分布函数(BRDF)模型;该模型通过引入镜向系数来表征表面散射的贡献程度,以改进传统的偏振BRDF模型,使得含5个参量(复折射率的实部和虚部、表面粗糙度、相对漫反射率系数、镜向系数)的新偏振BRDF模型更符合实际的涂层表面散射偏振特性;通过开展户外实验获得黑漆和绿漆涂层表面在不同观测几何时的偏振度,利用遗传算法从实测数据中反演关键参量。结果表明:对于不同的涂层表面,该多参量偏振BRDF模型的仿真结果与实测数据均能较好地吻合,引入镜向系数能够提高模型的准确性,可为涂层目标偏振特征的提取和有效识别提供依据。
物理光学 偏振特性 双向反射分布函数 Kubelka-Munk理论 涂层表面 偏振 散射偏振
Author Affiliations
Abstract
1 Air and Missile Defense College, Air Force Engineering University, Xi’an 710051, China
2 Department of Physics, Faculty of Science, Ningbo University, Ningbo 315211, China
3 School of Electronic Engineering and Computer Sciences, Peking University, Beijing 100871, China
4 School of Information Engineering, East China Jiaotong University, Nanchang 330013, China
5 School of Electronics and Information Engineering, Soochow University, Suzhou 215006, China
6 Advanced Technique Department, Key Laboratory of Aeronautics Computing Technique, Xi’an 710175, China
7 e-mail: tangshiwei@nbu.edu.cn
Safe detection of an arbitrarily shaped platform is critical for survivability, rescue, or navigation safety in a remote region. Metasurfaces afford great potential due to their strong electromagnetic (EM) wave control. However, studies have mainly focused on the physics and design of metasurfaces on planar plates, which does not satisfy the current requirements of aerodynamics and aesthetics. Herein, we propose a sophisticated strategy to design a metasurface that can wrap over arbitrarily shaped objects with moderate curvature on which optical aberrations are commonly introduced. By designing each meta-atom on the basis of the required position and phase compensation, exact EM wavefronts are restored. For verification, several conformal metasurfaces were designed and numerically studied on metallic cylinders at the microwave spectrum. A proof-of-concept device is fabricated and is experimentally characterized. The results demonstrate the availability of the desirable dual-beam superscatterer with strong backscattering enhancement toward two directions, thus indicating that the distortions induced by an arbitrary platform can be efficiently corrected. Our method affords an efficient alternative for designing high-performance multifunctional optoelectronic devices equipped on a moderately curved platform.
Metamaterials Scattering, polarization Artificially engineered materials Photonics Research
2018, 6(8): 08000782
Author Affiliations
Abstract
Institute of Electronic Engineering, China Academy of Engineering Physics, Mianyang 621900, China
A method of chromatic polarization imaging is presented for the online detection of colorless plastic contaminants from ginned cotton in an industrial setting. To understand the experimental results, we consider a realistic microscopic model, including the multiple scattering of anisotropic fibers and the light propagation in anisotropic slabs. A Monte Carlo code, based on the extended Jones matrix, is developed to simulate photon migration with polarization states, and phase information followed. Using simulations and experiments, we analyze the underlying mechanisms and evaluate the performance of this method with different layer thicknesses. Our approaches proposed in this Letter also have the potential to be applied in tissue imaging, remote sensing, and other scenarios.
290.5855 Scattering, polarization 290.7050 Turbid media 290.5850 Scattering, particles Chinese Optics Letters
2015, 13(9): 092901
1 无锡科技职业学院 电子工程学院，江苏 无锡 214028
2 河北工业大学 理学院，天津 300401
制备出应变调光玻璃样品，利用剪切装置对样品施加剪切应力后，样品呈散射偏光态。实验观察到样品所特有的在剪切力施加方向上透光率偏高的视角特性，通过建立理论模型并测试透光率随入射角变化曲线，得到了散射偏光玻璃透光率综合表达式，以及样品中液晶微滴倾斜角度与透光率关系。模拟计算表明，本文所建立的理论表达式能基本描述剪切液晶散射偏光玻璃特性。
剪切液晶 散射偏光玻璃 透光率 视角特性 sheared liquid crystal scattering polarization glass transmittance viewing angle characteristic
Author Affiliations
Abstract
Small particle light scattering can produce light with polarization characteristics different from those of the incident beam. An analytical solution to the scattering by a spheroid with inclusion for an on-axis polarized Gaussian beam incidence is provided within the generalized Lorenz-Mie theory framework. The shapes of the inclusion can be spherical, confocal spheroid, or non-confocal spheroid. The Muller scattering matrix elements are computed for plane wave incidence or Gaussian light beam incidence. The effect of the size and shape of the inclusion or the coating on the polarized Gaussian light scattering characteristics by a spheroidal water coating aerosol particle are computed and analyzed.
290.1090 Aerosol and cloud effects 290.1350 Backscattering 290.5850 Scattering, particles 290.5855 Scattering, polarization Chinese Optics Letters
2014, 12(1): 012901
国家海洋局第二海洋研究所卫星海洋环境动力学国家重点实验室, 浙江 杭州 310012
根据Mie散射理论，以对数正态分布函数描述沙尘气溶胶粒子群的粒径尺度分布，计算了沙尘气溶胶粒子群在0.2~40 μm波段间对太阳短波辐射和地球大气长波辐射的单次散射反照率、散射相矩阵函数，揭示了不同相对湿度时，沙尘粒子群对入射辐射的散射和偏振的特征。结果表明，沙尘粒子群的单次散射反照率随着入射波长的增加有较大起伏，不同相对湿度条件下，变化趋势基本一致；在可见光、近红外波段单次散射反照率随湿度增加而变大，湿度95%时非常接近于1；大于10 μm的热红外波段单次散射反照率随相对湿度增加而减小，具有较强的吸收辐射能力。散射辐射强度受湿度影响较小，随散射角的增加呈现先减小后增大的趋势，且增大的趋势随着波长的增加而减弱；不同波段上，线偏振和圆偏振随散射角和相对湿度变化存在差异；在前向和后向仅对入射辐射为圆偏振辐射产生圆偏振散射；散射光的偏振特性及其湿度差异主要表现在后向散射区，多以拱形形式体现。拱顶峰值散射角位置存在差异，且峰值散射角随相对湿度的降低向后向漂移。
大气光学 散射偏振 Mie理论 沙尘粒子群 单次散射反照率 相矩阵
Author Affiliations
Abstract
1 State Key Lab of Modern Optical Instrumentation, Zhejiang University, Hangzhou 310027, China
2 Department of Physics, Zhaoqing University, Zhaoqing 526061, China
Dielectric microspheres can confine light in a three-dimensional (3D) region called photonic nanojet is shown when they are illuminated by different polarized beams. The influence of incident light polarization on photonic nanojet using the finite-difference time-domain (FDTD) method is demostrated. The axial field intensity profiles of photonic nanojets for both the linear and circular polarization incident beams are very similar. Azimuthal polarization incident beam induces a doughnut beam along the optical axis, while the radial polarization incident beam permits one to reach an effective volume as small as 0.7(\lambda/n)3.
光子纳米喷射 时域有限元差分法 偏振态 290.5850 Scattering, particles 180.0180 Microscopy 290.5855 Scattering, polarization Chinese Optics Letters
2011, 9(7): 072901
Author Affiliations
Abstract
1 Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800, China
2 Graduate University of Chinese Academy of Sciences, Beijing 100049, China
The relations between scattering angle (SA) and the degree of polarization (DOP) of skylights are studied. Measurements under different sky conditions demonstrate that all relation curves between SA and DOP can be described as parabolas. DOP reaches its peak when SA is 90° and the sizes of scattering particles are much smaller than the wavelengths of skylight. The peak value of DOP moves by a small drift when the size of the particle increases. We propose and analyze a polarization dependence model for SA and DOP. Results from simulation are in good agreement with experimental results.
大气散射 偏振 散射角 010.1310 Atmospheric scattering 290.5855 Scattering, polarization 290.1310 Atmospheric scattering 290.4020 Mie theory Chinese Optics Letters
2010, 8(6): 546
