Electromagnetic diffraction radiation of a subwavelength-hole array excited by an electron beam

Abstract

This paper explores the physics of the electromagnetic diffraction radiation of a subwavelength holes array excited by a set of evanescent waves generated by a line charge of electron beam moving parallel to the array. Activated by a uniformly moving line charge, numerous physical phenomena occur such as the diffraction radiation on both sides of the array as well as the electromagnetic penetration or transmission below or above the cut-off through the holes. As a result the subwavelength holes array becomes a radiation array. Making use of the integral equation with relevant Green's functions, an analytical theory for such a radiation system is built up. The results of the numerical calculations based on the theory agree well with that obtained by the computer simulation. The relation among the effective surface plasmon wave, the electromagnetic penetration or transmission of the holes and the diffraction radiation is revealed. The energy dependence of and the influence of the hole thickness on the diffraction radiation and the electromagnetic penetration or transmission are investigated in detail. Therefore, a distinct diffraction radiation phenomenon is discovered.

Surface Polariton Cherenkov Light Radiation Source

“…Recently, intense investigation has demonstrated that the combination of electronics, photonics, and nanotechnology is a promising method to generate radiation, ranging from terahertz to visible light [1][2][3][4][5][6][7]. Among these studies, Refs.…”

The diffraction radiation of sub-wavelength holes array with dielectric medium loading

“…T has been shown that under the excitation of a line current of electron beam, the sub-wavelength holes array (SHA) becomes a diffraction radiation array, and the SHA diffraction radiation is a special mechanism with unique distinguished characteristics [1,2]. In this paper we reveal that the dielectric medium loading in the lower half-space of the array (SHAM) brings surprising changes to the behaviors of the diffraction radiation, furthermore many interesting and important phenomena occur.…”

“…Figure 1 shows the contour map of the diffraction radiation, which demonstrate that it is unique radiation behavior. In the upper half-space, the electrons excited the diffraction radiation as the structure without loading medium in reference [2]. However, in the lower half-space, the loading dielectric medium brings essential changes to the behaviors of the radiation.…”

High-harmonic terahertz radiation from prebunched electron beam in the tapered grating structure

“…One of the most important research areas in THz regime is the radiation sources, and in order to fill the THz gap the studies on this area are extremely intensive [1][2][3]. It seems linear electron-beam driven sources provide good ways to develop (approaches to) the compact and room temperature THz sources and there are a lot of published papers concerned the topics of backward-wave oscillators (BWO), extended interaction oscillators (EIO), orotron and free-electron lasers (FELs) and so on [4][5][6][7][8][9][10][11][12][13][14][15]. However, among these Electron-beam driven oscillator-sources, there is a key problem limited the development in THz regime: the starting current density.…”