Broadband Terahertz Modulators based on MEMS-Reconfigurable Mesh Filters

TL;DR

This paper presents a room-temperature, electrically reconfigurable meta-surface that modulates terahertz waves by switching its diamagnetic response, achieving high modulation depths and bandwidths.

Contribution

It introduces a novel class of meta-surfaces with electrically-induced diamagnetic switching at terahertz frequencies, enabling advanced terahertz modulation.

Findings

Significant change in relative permeability and permittivity.

High modulation depth and bandwidth achieved.

Room-temperature operation of the meta-surface.

Abstract

Active tuning and switching of electromagnetic properties of materials is of great importance for controlling their interaction with electromagnetic waves. Superconductors are the only natural materials that exhibit diamagnetic switching at their critical temperatures. Here, we demonstrate a new class of meta-surfaces with electrically-induced diamagnetic switching capability at room temperature. Structural configuration of the subwavelength meta-molecules determines their magnetic response to an external electromagnetic radiation. By reconfiguration of the meta-molecule structure, the strength of the induced magnetic field in the opposite direction to the external magnetic field is varied and the diamagnetic state of the meta-surface is altered, consequently. We demonstrate a significant change in the relative permeability and permittivity of a custom-designed meta-surface with diamagnetic switching capability at terahertz frequencies, enabling terahertz intensity modulation with record high modulation depths and modulation bandwidths through a fully integrated device platform at room temperature.