设计一种针对粗糙表面目标的基于稀疏限制的鬼成像(GISC)实验装置,研究并分析接收系统的数值孔径与粗糙目标尺寸对GISC成像性能的影响。结果表明,粗糙目标的GISC成像质量与接收系统的数值孔径和目标尺寸均呈正相关。本研究可以为GISC装置中接收系统的光路设计提供重要参考。

为了研究高斯粗糙表面偏振特性, 基于微面元理论, 综合考虑微面元的漫反射和镜面反射, 建立偏振双向反射分布函数模型。对由偏振双向反射分布函数得到的穆勒矩阵进行分解、变换等处理, 推导出表征粗糙表面二向色性、相位延迟和退偏的3个子矩阵及其对应的偏振特性表达式。针对典型的粗糙目标, 对偏振特性进行理论计算。分析入射角、方位角, 以及粗糙度对粗糙表面偏振特性的影响。结果表明：粗糙表面二向色性在入射角变化范围内有极大值, 且随方位角的增大而增大；相位延迟随入射角的增大而减小, 且在方位角变化范围内有极大值；退偏能力在入射角范围内有极小值, 且随方位角的增大而减小；粗糙度对除退偏能力以外的偏振特性影响较小。

A new criterion for target detection and identification is proposed to realize metal/dielectric identification and recognition based on Mueller matrix analysis. By using randomly rough surfaces as targets, numerical calculations are used to prove the robustness and accuracy of the criterion. Moreover, to the best of our knowledge, this is the first time to successfully explain the criterion by theoretical analysis. We believe the work provides an important reference for polarization imaging in laser radar and remote sensing, and so on.

A method of detecting dry, icy and wet road surface conditions based on scanning detection of single wavelength backward power is proposed in this letter. The detector is used to receive the backward scattered power which changes with the incidence angle. The relationship between backward power and incidence angle is used to find out the effective angle range and distinguish method. Experiment and simulation show that it is feasible to classify these three conditions within incidence angle of 5.3 degree.

A practicable experimental method for measuring scattering on rough surfaces is reported. The scattered patterns are captured on a screen composed of two pieces of ground glass and then imaged using a charge-coupled device. The scattered intensity profiles are extracted by converting the patterns in real space into the wave vector space. Isotropic and anisotropic samples of the rough backsides of silicon wafer are investigated respectively, and their intensity profiles are measured. The profiles of the anisotropic sample are obtained by reading the pixels on the specific orientation curves. The parameters of the samples are extracted using angle-resolved light-scattering schemes and theories. The results well agree with measurements obtained using an atomic force microscope.

Amorphous Si waveguides with gradient refractive index cladding structure are proposed and fabricated using plasma-enhanced chemical vapor deposition method. Compared with 6 dB/cm for ridge waveguide without gradient cladding, the propagation loss of the gradient cladding waveguides is less than 1 dB/cm with both TE and TM polarizations.

The optical wave scattering from one-dimensional (1D) lossy dielectric Gaussian random rough surface is studied. The tapered incident wave is introduced into the classical Kirchhoff approximation (KA), and the shadowing effect is also taken into account to make the KA results have a high accuracy. The definition of the bistatic scattering coefficient of the modified KA and the method of moment (MOM) are unified. The characteristics of the optical wave scattering from the lossy dielectric Gaussian random rough surface of different parameters are analyzed by implementing MOM.

The depolarization behavior of backscattered linearly polarized light from ZnO thin film was investigated experimentally. The results show that the characteristics are related to both the polarization orientation and wavelength of linearly polarized incident light. When the incident light is s-polarized, the depolarization behaviors are different for different wavelengths. When the incident light is p-polarized, the depolarization behaviors, on the contrary, are similar for different wavelengths. In addition, there is an optimal incident angle for depolarization of linearly polarized light with different wavelengths, which is equal to their effective Brewster angles, respectively.

Reflectance model is a basic concept in computer vision. Some existing models combining the classical diffuse reflectance model and those for surfaces containing specular components can approximately describe real reflectance. But the ratio of diffuse and specular reflection decided manually has no clear meaning. We propose a new polynomial hybrid reflectance model. The reflectance map equation with a known shape (for example cylinder) as a sample is used to estimate parameters of the proposed reflectance model by least square regression algorithm. Then the reflectance parameters for surfaces of the same class of materials can be determined. Experiments are performed for a metal surface. The synthesis images produced by the proposed method and existing ones are compared with the real acquired image, and the results show that the proposed reflectance model is suitable for describing real reflectance.

The optical wave scattering from the slightly rough surface of three-layer medium is studied. The formulaes of the scattering coefficients for different polarizations are derived using the small perturbation method. A Gaussian rough surface is presented for describing rough surface of layered medium, the influence of the permittivity of layered medium, the mean layer thickness of intermediate medium, the surface roughness parameters and the incident wavelength on the bistatic scattering coefficient of HH polarization are obtained and discussed by numerical implementation.