Transmission of doughnut light through a bull's eye structure

TL;DR

This paper experimentally demonstrates that doughnut-shaped light can pass through a bull's eye nanostructure with high efficiency, maintaining its shape despite the small hole size relative to the wavelength.

Contribution

It reveals the mechanism of extraordinary optical transmission of doughnut light through a bull's eye structure, highlighting surface plasmon excitation and shape preservation.

Findings

Transmission efficiency is about 57 times the input energy.

The transmitted light retains the doughnut shape.

Surface plasmons facilitate energy transfer through subwavelength holes.

Abstract

We experimentally investigate the extraordinary optical transmission of doughnut light through a bull's eye structure. Since the intensity is vanished in the center of the beam, almost all the energy reaches the circular corrugations (not on the hole), excite surface plasmons which propagate through the hole and reradiate photons. The transmitted energy is about 57 times of the input energy on the hole area. It is also interesting that the transmitted light has a similar spatial shape with the input light although the diameter of the hole is much smaller than the wavelength of light.