Terahertz Devices Using the Optical Activation of GeTe Phase Change Materials: Towards Fully Reconfigurable Functionalities

TL;DR

This paper demonstrates the optical activation of GeTe phase change materials to create highly reconfigurable, broadband THz devices with high extinction ratios, enabling advanced THz wave manipulation.

Contribution

It introduces a novel all-dielectric, optically controlled GeTe-based THz device with broadband response and high extinction ratio, advancing reconfigurable THz technology.

Findings

Successful optical control of GeTe phase states for THz modulation

Development of broadband GeTe-based THz polarizers with high extinction ratio

Potential for creating programmable metasurfaces and metamaterials

Abstract

We are demonstrating the optical control of a specific state of the germanium telluride (GeTe) phase change material and its integration as control element for realizing extremely efficient optically reconfigurable THz devices. The excellent contrast of the material THz electrical properties in the two dissimilar states were used for optical-induced fast modulation of THz resonances of a hybrid metamaterial based of arrays of split ring resonator metallic structures integrating GeTe patterns. We experimentally confirm for the first time the feasibility to develop all dielectric (metal free) GeTe-based THz polarizers presenting a broadband response, a high extinction ratio when the GeTe is in the metal-like phase (up to 16.5 dB) and almost transparent when the material is in the amorphous phase. The presented highly functional approach based on non-volatile, optically controlled multi-operational THz devices integrating PCMs, is extremely stimulating for generating disruptive developments like field-programmable metasurfaces or all-dielectric coding metamaterials with multifunctional capabilities for THz waves manipulation.