Geometrically decorated two-dimensional (2D) discrete surfaces can be more effective than conventional smooth reflectors in managing wave radiation. Constructive non-specular wave scattering permits the scattering angle to be other than twice that of incidence and can result in gross violations of the law of reflection. Hence significant fraction of the phase space becomes accessible. A wide range of novel reflective behaviors ensues; including the phenomenon of negative reflection were energy transport remains on the same side of the normal. Also, at a critical incidence coherent superposition can force both the transmitted and reflected waves to graze the scattering surface thus synergistically reinforcing the diffractive process in a behavior reminiscent of critical internal reflection of ray optics. We experimentally demonstrate the concept with measurements on a one-dimensionally periodic system (grating) where the scattering angle is shown to be an inverse circular function of a function that depends on the diffractive index and the two angles. Excellent agreement is found between experimental data and theory.
IR radiometer sensitivity and accuracy improvement by eliminating spurious radiation for emissivity measurements on highly specular samples in the 2 to 25 μm spectral range
Fraunhofer Institute of Optronics, System Technologies and Image Exploitation IOSB（弗劳恩霍夫光电、系统技术与图像利用研究所IOSB）；Karlsruhe Institute of Technology（卡尔斯鲁厄理工学院）
3D Imaging of Complex Specular Surfaces by Fusing Polarimetric and Deflectometric Information
Wyant College of Optical Sciences, University of Arizona（亚利桑那大学怀亚特光学科学学院）；Department of Electrical and Computer Engineering, Northwestern University（西北大学电气与计算机工程系）
Subspace identification of low-dimensional Structural-Thermal-Optical-Performance (STOP) models of reflective optics
本文研究了利用子空间系统辨识技术估计反射光学系统瞬态结构-热-光性能（STOP）模型的可行性。作为一个测试案例，我们使用牛顿望远镜结构。这项工作的动机是需要开发基于模型的数据驱动技术，用于预测，估计和控制光学系统中的热效应和热诱导波前像差，如地面和空间望远镜，在恶劣环境中工作的光学仪器，光学光刻机，和高功率激光系统的光学部件。我们估计和验证一个瞬态STOP动态的状态空间模型。首先，我们在COMSOL Multiphysics中对系统进行建模。然后，我们使用LiveLink for MATLAB软件模块将波前像差数据从COMSOL导出到MATLAB。该数据用于测试Python中实现的子空间识别方法。STOP模型的建模和估计的主要挑战之一是它们本质上是高维的。STOP模型的大尺度性质源于光学、热学和结构现象与物理过程的耦合。我们的研究结果表明，所考虑的光学系统的高维STOP动力学可以准确地估计低维状态空间模型。由于它们的低维性质和状态空间形式，这些模型可以有效地用于预测，估计和控制热诱导波前像差。开发的MATLAB、COMSOL和Python代码可在线获得。
Surface figure metrology for reflective membrane mirrors based on phase-measuring deflectometry
College of Science, Nanjing University of Posts and Telecommunications（南京邮电大学理学院）；Purple Mountain Observatory, Chinese Academy of Sciences（中国科学院紫金山天文台）
