Enhanced transmission through metallic plates perforated by arrays of subwavelength holes and sandwiched between dielectric slabs

Abstract

This paper presents analytical and numerical studies demonstrating that a perfectly conducting metallic plate perforated by a periodic array of subwavelength holes and sandwiched in between two dielectric slabs permits enhanced transmission of electromagnetic plane waves in both the optical and microwave regimes, and this for both transverse magnetically and electrically polarized fields. The enhanced transmission mechanism is attributed to coupling between the incident plane wave and resonances supported by the perforated plate that are associated with the existence of grounded dielectric slab guided waves. The enhanced transmission phenomenon occurs in one of two regimes. In the single resonance regime, the incident plane wave couples to a resonance supported by only a single slab. The transmission coefficient magnitude peaks as the excitation frequency scans through the resonance; however, the peak magnitude decays exponentially with plate thickness. In the double resonance regime, the incident plane wave couples to resonances in both slabs simultaneously. The transmission coefficient magnitude exhibits twin peaks whose magnitudes typically are larger than those resulting from single resonances and that remain large even for plates of moderate thickness. It is demonstrated that double resonances may occur for symmetric as well as for asymmetric structures, i.e., when the two slabs are identical or different. For symmetric structures double resonances occur for any angle of incidence. In contrast, for asymmetric structures, special conditions on the period and slab parameters have to be satisfied for the structure to support one or more double resonances.

Extraordinary Magneto-Optical Effects and Transmission through Metal-Dielectric Plasmonic Systems

“…In Ref. 9 optical transmission through a perforated metallic film in the presence of an external magnetic field applied in the film plane was studied and a strong dependence of the EOT-peak position on both the magnitude and direction of the in-plane magnetic field was found. Recently, experiments on perforated Co films have also been conducted [11].…”

“…Along with SPPs some other types of slow waves can be involved into the EOT, e.g. guided waves or surface waves supported by arrays of holes [9].…”

Resonant terahertz transmissions through metal hole array on silicon substrate

“…These ET modes generally appear at frequencies close to that of the Wood's anomaly and the attendant Bragg surface wave is bound close to the metal surface [17]. In our case, the silicon layer supports guided modes with low loss propagation parallel to the metal surface.…”

Breaking the diffraction barrier outside of the optical near-field with bright, collimated light from nanometric apertures

“…Studies and numerical simulations in the near-field are an active area of investigation (11-13). Far-field numerical simulations and measurements of light through these nanoholes have been accomplished in numerous investigations (13)(14)(15)(16)(17)(18)(19)(20). Some data about the meso-field (between far-field and near-field) can be deduced from both sets of studies.…”

“…Janssen et al (21) explored this region in numerical modeling of multiple slits in metals. It is often recognized that slit arrays, although they can provide some insight into the phenomenon of extraordinary optical transmission (EOT) in hole arrays, cannot sufficiently explain it because slits can support transverse electric and magnetic (TEM) modes; and, therefore, the transmission properties of slit arrays in metal will most likely be different from those in hole arrays in the same metal (20,22). To gain experimental access to this poorly understood length regime, we fabricated two classes of test structures constructed of optically thick metallic films deposited on substrates or superstrates.…”