Electromagnetic resonant properties of metal-dielectric-metal (MDM) cylindrical microcavities

Abstract

Optical metamaterials can concentrate light into extremely tiny volumes to enhance their interaction with quantum objects. In this paper, a cylindrical microcavity based on the Au-dielectric-Au sandwiched structure is proposed. Numerical study shows that the cylindrical microcavity has the strong ability of localizing light and confining 10 3 --10 4 -fold enhancement of the electromagnetic energy density, which contains the most energy of the incoming light. The enhancement factor of energy density G inside the cavity shows the regularities as the change in the thickness of the dielectric slab, dielectric constant, and the radius of gold disk. At the normal incidence of electromagnetic radiation, the obtained reflection spectra operate in the range from 4.8 μm to 6 μm and with the absorption efficiency C (C=1-R min ), which can reach 99% by optimizing the structure's geometry parameters, and the dielectric constant. Due to the symmetry of the cylindrical microcavities, this structure is insensitive to the polarization of the incident wave. The proposed optical metamaterials will have potential applications in the surface enhanced spectroscopy, new plasmonic detectors, bio-sensing, solar cells, etc.

A study on refractive index sensors based on optical micro-ring resonators

“…In recent years, the use of photonic nano-sensors as bio-sensors is a hot topic of research, with a plethora of designs and applications [18][19][20][21][22][23]. Therefore, in the following, the behavior of the system described in the previous section as biosensor is considered.…”