Panel transmission measurements: The influence of the non plane wave nature of the incident field

2008 ◽  
Vol 123 (5) ◽  
pp. 3591-3591 ◽  
Author(s):  
Victor F. Humphrey ◽  
John Smith
Keyword(s):  
Plane Wave ◽  
Incident Field ◽  
Wave Nature ◽  
Transmission Measurements

scholarly journals Asymmetric Diffraction in Plasmonic Meta-Gratings Using an IT-Shaped Nanoslit Array

Sensors ◽  
2021 ◽  
Vol 21 (12) ◽  
pp. 4097
Author(s):  
Hee-Dong Jeong ◽  
Seong-Won Moon ◽  
Seung-Yeol Lee
Keyword(s):  
Plane Wave ◽  
Periodic Structures ◽  
Single Layer ◽  
Optical Diffraction ◽  
Back Side ◽  
Infrared Band ◽  
Effective Period ◽  
Wave Nature ◽  
Control Light ◽  
Meta Atom

Diffraction is a fundamental phenomenon that reveals the wave nature of light. When a plane wave is transmitted or reflected from a grating or other periodic structures, diffracted light waves propagate at several angles that are specified by the period of the given structure. When the optical period is shorter than the wavelength, constructive interference of diffracted light rays from the subwavelength-scale grating forms a uniform plane wave. Many studies have shown that through the appropriate design of meta-atom geometry, metasurfaces can be used to control light properties. However, most semitransparent metasurfaces are designed to perform symmetric operation with regard to diffraction, meaning that light diffraction occurs identically for front- and back-side illumination. We propose a simple single-layer plasmonic metasurface that achieves asymmetric diffraction by optimizing the transmission phase from two types of nanoslits with I- and T-shaped structures. As the proposed structure is designed to have a different effective period for each observation side, it is either diffractive or nondiffractive depending on the direction of observation. The designed structure exhibits a diffraction angle of 54°, which can be further tuned by applying different period conditions. We expect the proposed asymmetric diffraction meta-grating to have great potential for the miniaturized optical diffraction control systems in the infrared band and compact optical diffraction filters for integrated optics.

Rigorous accounting diffraction on non-plane gratings irradiated by non-planar waves

2021 ◽  
Author(s):  
Leonid I. Goray
Keyword(s):  
Plane Wave ◽  
Wave Diffraction ◽  
Plane Waves ◽  
Three Dimensional ◽  
Integral Equation Method ◽  
Transverse Magnetic ◽  
Incident Field ◽  
Boundary Integral ◽  
Cylindrical Waves ◽  
Plane Wave Diffraction

Abstract The modified boundary integral equation method (MIM) is considered a rigorous theoretical application for the diffraction of cylindrical waves by arbitrary profiled plane gratings, as well as for the diffraction of plane/non-planar waves by concave/convex gratings. This study investigates two-dimensional (2D) diffraction problems of the filiform source electromagnetic field scattered by a plane lamellar grating and of plane waves scattered by a similar cylindrical-shaped grating. Unlike the problem of plane wave diffraction by a plane grating, the field of a localised source does not satisfy the quasi-periodicity requirement. Fourier transform is used to reduce the solution of the problem of localised source diffraction by the grating in the whole region to the solution of the problem of diffraction inside one Floquet channel. By considering the periodicity of the geometry structure, the problem of Floquet terms for the image can be formulated so that it enables the application of the MIM developed for plane wave diffraction problems. Accounting of the local structure of an incident field enables both the prediction of the corresponding efficiencies and the specification of the bounds within which the approximation of the incident field with plane waves is correct. For 2D diffraction problems of the high-conductive plane grating irradiated by cylindrical waves and the cylindrical high-conductive grating irradiated by plane waves, decompositions in sets of plane waves/sections are investigated. The application of such decomposition, including the dependence on the number of plane waves/sections and radii of the grating and wave front shape, was demonstrated for lamellar, sinusoidal and saw-tooth grating examples in the 0th & –1st orders as well as in the transverse electric and transverse magnetic polarisations. The primary effects of plane wave/section partitions of non-planar wave fronts and curved grating shapes on the exact solutions for 2D and three-dimensional (conical) diffraction problems are discussed.

On Maxwell's equations in non-stationary media

2008 ◽  
Vol 366 (1871) ◽  
pp. 1781-1788 ◽  
Author(s):  
I Vorgul
Keyword(s):  
Analytical Solution ◽  
Plane Wave ◽  
Integral Equations ◽  
Maxwell’S Equations ◽  
Maxwell's Equations ◽  
Exact Analytical Solution ◽  
Charge Injection ◽  
Incident Field ◽  
Volterra Integral Equations ◽  
Numerical Investigations

Maxwell's equations formulated for media with gradually changing conductivity are reduced to Volterra integral equations. Analytical and numerical investigations of the equations are presented for the case of gradual splash-like change in conductivity. Splash-like change in medium parameters can model any discharge phenomena, growing plasma, charge injection, etc. Exact analytical solution for the resolvent is presented and different field behaviours are analysed for the incident field as a plane wave and as an impulse.

High frequency diffraction by a soft circular disc

1972 ◽  
Vol 71 (3) ◽  
pp. 545-565
Author(s):  
J. C. Newby
Keyword(s):  
Integral Equation ◽  
Plane Wave ◽  
Infinite Number ◽  
High Frequency ◽  
Normal Wave ◽  
Incident Field ◽  
Fourier Component ◽  
Incident Plane Wave ◽  
Oblique Wave ◽  
Incident Plane

AbstractInitially a general incident field is considered and the equations are split into Fourier components. Each Fourier component gives rise to an integral equation similar to that obtained when investigating diffraction of a normally incident plane wave. After the oblique wave has been specified an analysis similar to that used for the normal wave leads to a solution of the problem containing an infinite number of constants. It is shown, however, that these constants do not affect the leading terms of the high frequency scattering coefficient.

The scintillation of extended radio sources when the receiver has a finite bandwidth

1970 ◽  
Vol 316 (1526) ◽  
pp. 315-339 ◽  
Keyword(s):  
Plane Wave ◽  
Autocorrelation Function ◽  
Scattered Field ◽  
Angular Size ◽  
Single Scattering ◽  
Incident Field ◽  
Scintillation Index ◽  
Spatial Frequencies ◽  
Extended Radio ◽  
Fourier Integrals

Many treatments of wave scattering by irregular media take the incident field to be that of a monochromatic plane wave. There are, however, important cases encountered in practice, in particular in Radio Astronomy, when the incident field is not a plane wave, but is produced by a source of a finite angular size. Moreover, the radiation is not monochromatic, but is received over a continuous band of frequencies. The present paper is concerned with fluctuations produced when such a field is scattered by a medium containing weak random irregularities of refractive index. The important statistical properties of these fluctuations are shown to depend on three quantities which are double Fourier integrals with respect to the spatial frequencies present in the scattered field. These functions are assembly averages of products of scattered field components, and are derived by studying the scattering of a wave obliquely incident on a weakly irregular medium. Physical considerations are used to show how a spread of frequencies and angles of arrival, in the incident wave, affect the fluctuations imposed by the medium. The integrands of the Fourier integrals can be used later for the general problem of multiple scatter, but the results in this paper are only for weak single scattering, when the scatterer is either a thin phase changing screen or an extended irregular medium. Formulae are given for the scintillation index, the scintillation visibility, and the spatial autocorrelation function of the fluctuations of received intensity, for some particular cases of source brightness function, receiver bandpass function and autocorrelation function of irregularities in the medium. They are discussed briefly, to illustrate some properties of fluctuations of the scattered field when the incident field is only partially coherent.

scholarly journals Reflection of a Wave by a Cylindrical Mirror

1956 ◽  
Vol 9 (3) ◽  
pp. 145-150 ◽  
Author(s):  
Ll. G. Chambers
Keyword(s):  
Plane Wave ◽  
Scattered Field ◽  
Incident Field ◽  
Wave Incident ◽  
Two Dimensional ◽  
Cylindrical Mirror ◽  
Plane Wave Incident

The question of the reflection of a wave by a cylindrical mirror is of interest in a number of fields. It is a problem in which it is difficult to obtain an expression for the reflected or scattered field without recourse to physical assumptions which are sometimes somewhat dubious. An attempt was made by Sommerfeld to solve the problem of a plane wave incident upon such a perfectly conducting mirror by means of what he termed the “Non-Final Determination of Coefficients”. Unfortunately, a close examination of the problem renders it doubtful whether the method can be legitimately employed. It is possible, however, to solve the problem by expressing the scattered field in terms of the currents produced in the mirror, and finding the current generated in the mirror by an arbitrary incident field. The problem which we shall consider is the following two- dimensional one.

Historical Introduction

1977 ◽  
Vol 35 ◽  
pp. 2-5
Author(s):  
R. D. Heidenreich
Keyword(s):  
Electron Emission ◽  
Secondary Electron ◽  
Secondary Electron Emission ◽  
50Th Anniversary ◽  
Secondary Emission ◽  
Wave Nature ◽  
Nobel Prize In Physics ◽  
Primary Electrons ◽  
The U.S ◽  
Mutual Agreement

This program has been organized by the EMSA to commensurate the 50th anniversary of the experimental verification of the wave nature of the electron. Davisson and Germer in the U.S. and Thomson and Reid in Britian accomplished this at about the same time. Their findings were published in Nature in 1927 by mutual agreement since their independent efforts had led to the same conclusion at about the same time. In 1937 Davisson and Thomson shared the Nobel Prize in physics for demonstrating the wave nature of the electron deduced in 1924 by Louis de Broglie.The Davisson experiments (1921-1927) were concerned with the angular distribution of secondary electron emission from nickel surfaces produced by 150 volt primary electrons. The motivation was the effect of secondary emission on the characteristics of vacuum tubes but significant deviations from the results expected for a corpuscular electron led to a diffraction interpretation suggested by Elasser in 1925.

Theory and Errors in Stereo Electron Microscopy

1968 ◽  
Vol 26 ◽  
pp. 336-337
Author(s):  
J. M. Pankratz
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Plane Wave ◽  
Focal Length ◽  
Foil Thickness ◽  
Points Of Interest ◽  
Transmission Electron ◽  
Vertical Spacing ◽  
Illuminating System

It is often desirable in transmission electron microscopy to know the vertical spacing of points of interest within a specimen. However, in order to measure a stereo effect, one must have two pictures of the same area taken from different angles, and one must have also a formula for converting measured differences between corresponding points (parallax) into a height differential.Assume (a) that the impinging beam of electrons can be considered as a plane wave and (b) that the magnification is the same at the top and bottom of the specimen. The first assumption is good when the illuminating system is overfocused. The second assumption (the so-called “perspective error”) is good when the focal length is large (3 x 107Å) in relation to foil thickness (∼103 Å).

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