Physical optics

About: Physical optics is a research topic. Over the lifetime, 5342 publications have been published within this topic receiving 101388 citations. The topic is also known as: wave optics.

Scattering cross sections for composite surfaces that cannot be treated as perturbed-physical optics problems

Abstract: Perturbation and physical optics theories have traditionally been used to derive the scattering cross sections for composite surfaces that can be regarded as small-scale surface perturbations that ride on filtered, large-scale surfaces. In this case, perturbation theory accounts for Bragg scattering, while physical optics theory accounts for specular point scattering. However, for a more general class of composite surfaces that cannot be decomposed in such a manner, the perturbed–physical optics approach cannot be used. In these cases, it is shown, using the full wave approach, that the specular scattering associated with a filtered surface (consisting of the larger-scale spectral components) is strongly modified and that Bragg scattering and specular point scattering begin to blend with each other. Since the full wave solution accounts for Bragg scattering as well as specular point scattering in a self-consistent manner, it is not necessary to filter (decompose) the composite surface to evaluate the scattering cross sections in the general case. However, filtering the composite surface enhances one's physical insight as to the validity (or lack thereof) of the perturbed-physical optics decomposition and also facilitates the numerical evaluation of the scattering cross sections.

Principles of Bragg-Fresnel multilayer optics

Abstract: The paper describes the principles and theoretical models of new X-ray optical elements based on the behaviour of Bragg-Fresnel diffraction The use of volume diffraction permits one to achieve better spatial resolution compared with conventional plane optics and bending mirrors The construction of Bragg-Fresnel elements combines the advantages of high-resolution Fresnel optics with stability of multilayer mirrors

Incoherent Optical Processing

Abstract: In this chapter we have analyzed the basic characteristics of incoherent optical processing, considering three major classes of systems: (1) systems that rely on diffraction; (2) systems that rely on plane-to-plane imaging in the geometrical optics sense; and (3) systems that rely on diffractionless geometrical optics “shadow casting” for their operation. Incoherent systems are often characterized by a redundancy and immunity to noise not associated with coherent optical systems. However, the non-negative real nature of the information-bearing irradiance distributions precludes direct implementation of incoherent systems in many signal processing applications, and various tricks must be employed. Dynamic range limitations with incoherent systems are an area of active study, and the relative advantages of incoherent systems over coherent systems are not known conclusively.

Asymptotic High Frequency Methods

Abstract: Fundamental concepts of asymptotic high frequency(HF) techniques including geometrical optics(GO), physical optics(PO), geometrical theory of diffraction(GTD) and its uniform version(UTD), and physical theory of diffractions(PTD) are reviewed in this Chapter. Instead of going through mathematical derivations, important concepts will be summarized only to demonstrate the physical natures of asymptotic HF techniques. Examples of practical application will be presented to appreciate their usefulness.

A Combination of Time Domain Finite Element-Boundary Integral and with Time Domain Physical Optics for Calculation of Electromagnetic Scattering of 3-D Structures

Abstract: This paper presents a hybrid numerical approach combining an improved Time Domain Finite Element-Boundary Integral (FE-BI) method with Time Domain Physical Optics (TDPO) for calculations of electromagnetic scattering of 3-D combinative- complex objects. For complex-combined objects containing a small size and large size parts, using TDPO is an appropriate approach for coupling between two regions. Therefore, our technique calculates the objects complexity with the help of FE-BI and the combinatory structures by using of the TDPO. The hybridization algorithm for restrictive object is implemented and the numerical results validate the superiority of the proposed algorithm via realistic electromagnetic applications.