Novel electromagnetic radiation in a semi-infinite space filled with a double-negative metamaterial

Abstract

We have theoretically investigated the electromagnetic radiation excited by a charged particle moving along a semi-infinite space filled with a double-negative metamaterial (DNM). Cherenkov radiation in the double-negative region exhibits reversed or backward radiation behavior. The spectral density of reversed Cherenkov radiation (RCR) has a continuous distribution over the radiation frequency region. The influence of some important parameters on the Cherenkov radiation energy per unit length has been discussed. The surface wave in the vacuum region presented here also is investigated. We conclude that the amplitude of the surface wave is greatly enhanced over some normal dielectric materials cases. The enhanced surface wave may be useful for high frequency and high power vacuum electron devices with the DNM.

Sub-wavelength waveguide loaded by a complementary electric metamaterial for vacuum electron devices

“…MTMs and photonic crystals built of metallic parts can be considered as modified coupled-cavity or ladder structures and are promising for application in TWTs or BWOs. The wave-electron beam interaction in MTMs has been theoretically studied in [8][9][10][11][12][13][14][15]. Here we focus on the MTM-loaded waveguide and its application as an interaction circuit for a vacuum electron device.…”

Controlled steering of Cherenkov surface plasmon wakes with a one-dimensional metamaterial

“…By substituting in equation (4) and recalling that the phase gradient is given by equation (5), we find that From equation (6), we note that by decreasing the phase velocity of the excitation, that is, by increasing the magnitude of the denominator, one could access an interesting new regime in which a propagating polarization wave, with dispersion given by ω = c RWP,gen k, exists along the line of apertures without creating any SPP wakes. Such a subplasmonical regime is connected to the recent work by Sun et al and Qu et al, in which the authors studied the propagation of waves guided along gradient-index metasurfaces and their re-radiation into free space [26][27][28] .…”

Double negative-metamaterial based Terahertz radiation excited by a sheet beam bunch

“…Previously, we have studied the electromagnetic radiation excited by a single charged particle. 19 It clearly shows that the amplitude of the surface wave (SW), which is electromagnetic wave propagating along the surface of the DNM and exponentially decays far away from the interface between the vacuum and the DNM, can be enhanced when the RCR occurs in the DNM, relative to that of normal dielectric material cases, as shown in Ref. 19.…”

“…Therefore, the metamaterial-based electromagnetic emissions have been actively investigated worldwide. [9][10][11][12][13][14][15][16][17][18][19][20] The study results show that these novel electromagnetic radiations have potential applications such as in the detection of charged particles or in the radiation sources.…”

“…19 It clearly shows that the amplitude of the surface wave (SW), which is electromagnetic wave propagating along the surface of the DNM and exponentially decays far away from the interface between the vacuum and the DNM, can be enhanced when the RCR occurs in the DNM, relative to that of normal dielectric material cases, as shown in Ref. 19. In order to further enhance the THz radiation, it is more advantageous to employ a sheet beam bunch for THz radiation.…”