Cavity modes and their excitations in elliptical plasmonic patch nanoantennas

Abstract

We present experimental and theoretical studies of two dimensional periodic arrays of elliptical plasmonic patch nanoantennas. Experimental and simulation results demonstrate that the azimuthal symmetry breaking of the metal patches leads to the occurrence of even and odd resonant cavity modes and the excitation geometries dependent on their modal symmetries. We show that the cavity modes can be described by the product of radial and angular Mathieu functions with excellent agreements with both simulations and experiments. The effects of the patch periodicity on the excitation of the surface plasmon and its coupling with the cavity modes are also discussed.

Surface-Enhanced Two-Photon Excitation Fluorescence of Various Fluorophores Evaluated Using a Multiphoton Microscope

“…Altering the period, depth, and width of the structures changed the wavelength, FWHM, and amplitude of the resonance peak in a similar manner as to that previously reported [26], [30], [31], [41], [42]. Figs.…”

Plasmonic Nanostructure Arrays Coupled with a Quantum Emitter

“…A nanocavity with an elliptical shape, fabricated at the center of the nanostructure, can be designed to control the polarization state of the output light. In this example, the modes from the nanocavity are expressed by the product of even and odd functions from the radial part of the Mathieu functions [146,147]: 4 is a gap function of the wave vector k gsp and the focal length, f, of the nanostructure, Ce m (η, q) with m ! 0 and Se m (η, q) with m !…”

Resonant cavity modes of circular plasmonic patch nanoantennas

“…Recently, we investigated the cavity modes and their excitation conditions of elliptical patch nanoantennas. 16 We have shown that the electrical field distributions of the cavity modes can be described by the product of the radial and angular Mathieu functions. The cavity resonant frequencies can be related to the patch sizes and the dielectric gap thickness by simple resonant conditions when coupling effects are minimal.…”

“…[11][12][13] Advances in nanofabrication techniques have enabled high precision engineering of a myriad type of antennas, including Hertzian dipole, bowtie, Yagi-Uda, and patch nanoantennas. [14][15][16][17] The patch nanoantennas, which are composed of metallic disks on top of a metallic film with a dielectric layer, exhibit unique properties, such as near-perfect absorption, [18][19][20][21] high refractive index sensing, 18 ultra-small mode volumes, 22 polarization conversion, 17,23,24 and beam focusing. 25 Patches with different geometric shapes, such as circular, 26,27 elliptical, 16,20 squares, 28 and crosses, 23,24 have been studied.…”