# Actively tunable terahertz electromagnetically induced transparency analogue based on vanadium-oxide-assisted metamaterials

## TL;DR

This paper demonstrates active control of terahertz EIT analogue using vanadium oxide metamaterials, enabling dynamic modulation of transparency, group delay, and quality factor for advanced THz communication applications.

## Contribution

It introduces a novel active EIT control method employing VO2 for tunable THz metamaterials, enhancing modulation capabilities and multi-channel functionalities.

## Key findings

- Active modulation of EIT peak amplitude using VO2's phase transition.
- Dynamic tuning of group delay within the EIT window.
- Active control of EIT quality factor across broadband frequencies.

## Abstract

Recently, phase-change materials (PCMs) have drawn more attention due to the dynamically tunable optical properties. Here, we investigate the active control of electromagnetically induced transparency (EIT) analogue based on terahertz (THz) metamaterials integrated with vanadium oxide (VO2). Utilizing the insulator-to-metal transition of VO2, the amplitude of EIT peak can be actively modulated with a significant modulation depth. Meanwhile the group delay within the transparent window can also be dynamically tuned, achieving the active control of slow light effect. Furthermore, we also introduce independently tunable transparent peaks as well as group delay based on a double-peak EIT with good tuning performance. Finally, based on broadband EIT, the active tuning of quality factor of the EIT peak is also realized. This work introduces active EIT control with more degree of freedom by employing VO2, and can find potential applications in future wireless and ultrafast THz communication systems as multi-channel filters, switches, spacers, logic gates and modulators.

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Source: https://tomesphere.com/paper/1905.10623