Waveguide properties of single subwavelength holes demonstrated with radially and azimuthally polarized light

TL;DR

This study demonstrates that the transmission of focused radially and azimuthally polarized light through single subwavelength holes in a silver film can be accurately described by a classical waveguide model, even for very thin films.

Contribution

It shows that classical waveguide theory applies to subwavelength holes in metal films for specific polarizations and thinness, bridging experimental observations with theoretical models.

Findings

Waveguide modes are excited by specific polarization states.

Classical waveguide model explains transmission in thin silver films.

Transmission properties match theoretical predictions even at quarter-wavelength thickness.

Abstract

We investigate the transmission of focused beams through single subwavelength holes in a silver film. We use radially and azimuthally polarized light, respectively, to excite higher order waveguide modes as well as to match the radial symmetry of the aperture geometry. Remarkably, the transmission properties can be described by a classical waveguide model even for thicknesses of the silver film as thin as a quarter of a wavelength.