Dielectric microscopy with submillimeter resolution

TL;DR

This paper introduces a dielectric microscopy technique using tapered dielectric waveguides as probes in a millimeter wave vector network analyzer, achieving sub-wavelength spatial resolution for mapping dielectric properties of heterogeneous materials.

Contribution

The paper presents a novel dielectric microscopy method with sub-wavelength resolution using tapered dielectric waveguides and a 150 GHz probe, enabling detailed dielectric mapping of complex materials.

Findings

Achieved ~500 micron spatial resolution at 150 GHz

Successfully mapped dielectric properties of granite and oil shale

Demonstrated applicability to highly heterogeneous materials

Abstract

In analogy with optical near-field scanning methods, we use tapered dielectric waveguides as probes for a millimeter wave vector network analyzer. By scanning thin samples between two such probes we are able to map the spatially varying dielectric properties of materials with sub-wavelength resolution; using a 150 GHz probe in transmision mode we see spatial resolution of around 500 microns. We have applied this method to a variety of highly heterogeneous materials. Here we show dielectric maps of granite and oil shale.