Spatial mapping and tuning of terahertz modes in a silicon whispering gallery mode resonator

TL;DR

This paper demonstrates a method to map and manipulate terahertz modes in silicon whispering gallery resonators using perturbation techniques, enabling targeted mode tuning despite uncertainties in material parameters.

Contribution

It introduces an experimental approach for spatial mapping of terahertz modes and a design strategy for mode manipulation in silicon resonators.

Findings

Successful mapping of terahertz modes using a metal needle perturbation

Design of patterned structures for targeted mode manipulation

Potential for precise mode tuning in silicon resonators

Abstract

Identification and subsequent manipulation of resonant modes typically relies on comparison with calculations which require precise knowledge of material parameters and dimensions. For millimetre-sized resonators that support millimetre-wave modes, this is particularly challenging due to the poorly determined physical parameters and additional perturbative effects of nearby dielectric or metallic substrates in experimental setups. Here, we use perturbation from a metal needle to experimentally map the spatial distribution of terahertz modes in a silicon disc resonator. We then use this information to design a patterned structure to manipulate specific modes in the system, a technique that could be useful for targeted tuning of such modes.