Optical guided dispersions and subwavelength transmissions in dispersive plasmonic circular holes

TL;DR

This paper numerically investigates dispersive plasmonic circular holes, analyzing how hole diameter affects guided modes and dispersion, with comparisons to planar and perfect conductor structures, revealing insights into subwavelength light transmission.

Contribution

It provides a detailed numerical analysis of guided dispersion in dispersive plasmonic circular holes, including mode behavior and comparisons with related structures, advancing understanding of subwavelength guidance.

Findings

Guided modes depend on hole diameter and metal dispersion properties.

Comparison shows differences between circular holes, planar gaps, and perfect conductors.

Modal behavior varies with hole size and mode type.

Abstract

The light transmission through a dispersive plasmonic circular hole is numerically investigated with an emphasis on its subwavelength guidance. For a better understanding of the effect of the hole diameter on the guided dispersion characteristics, the guided modes, including both the surface plasmon polariton mode and the circular waveguide mode, are studied for several hole diameters, especially when the metal cladding has a plasmonic frequency dependency. A brief comparison is also made with the guided dispersion characteristics of a dispersive plasmonic gap [K. Y. Kim, et al., Opt. Express 14, 320-330 (2006)], which is a planar version of the present structure, and a circular waveguide with perfect electric conductor cladding. Finally, the modal behavior of the first three TM-like principal modes with varied hole diameters is examined for the same operating mode.