Corrugated probe for SNOM - Optimization of energy throughput via plasmon excitation

TL;DR

This paper introduces a corrugated probe design for SNOM that enhances energy throughput by exciting surface plasmons, potentially improving resolution through smaller apex diameters.

Contribution

It proposes a novel corrugated metal-coated fiber probe design that facilitates plasmon excitation to increase energy transport in SNOM.

Findings

FDTD simulations show increased energy throughput with corrugated probes.

Corrugated design enables smaller apex diameters for higher resolution.

Proposed fabrication method via glass etching is feasible.

Abstract

In a previous paper we proposed a modification of metal-coated tapered-fibre aperture probes for scanning near-field optical microscopes. The modification consists of radial corrugations of the metal-dielectric interface oriented inward the core. Their purpose is to facilitate the excitation of propagating surface plasmons, which increase the transport of energy beyond the cut-off diameter and radiate a quasi-dipolar field from the probe output rim. An increase in energy output allows for reduction of the apex diameter, which is the main factor determining the resolution of the microscope. In FDTD simulations we analyse the performance of the new type to SNOM probe. We aim at achieving of maximum energy throughput in probes with corrugations that may be realized in a glass etching process.