Graphene Metamaterials Based Plasmon-Induced Terahertz Modulator for High-Performance Multiband Filtering and Slow Light Applications

TL;DR

This paper presents multilayered graphene-based terahertz modulators with high group delay, broad tunability, and large extinction ratio, advancing multiband filtering and slow light applications in photonics.

Contribution

The study introduces a novel design of graphene metamaterial modulators with significantly improved group delay, tunability, and extinction ratio compared to previous works, using FDTD simulations.

Findings

Maximum group delay of 1.02 ps and 1.41 ps for quadband and pentaband modulators.

Maximum extinction ratio of 22.3 dB.

High sensitivity to polarization angle variations.

Abstract

We proposed multilayered graphene (Gr)-based surface plasmon resonance-induced high-performance terahertz (THz) modulators with tunable resonance frequencies. Several THz plasmonic modulators based on Gr metamaterials were previously reported; however, these modulators had small group delay, low extinction ratio (ER), and difficult-to-tune resonant frequency without structural parameters in the THz range. A comprehensive investigation employing the finite-difference time-domain (FDTD) simulation technique revealed high group delay, broad tunability independent of structural parameters, and large ER for our proposed quadband and pentaband plasmonic modulators. We obtained tunable group delays with a maximum of 1.02 ps and 1.41 ps for our proposed quadband and pentaband plasmonic modulators, respectively, which are substantially greater compared to previously reported Gr-based metamaterial structures. The maximum ER of 22.3 dB was obtained which was substantially high compared to previous reports. Our proposed modulators were sensitive to the polarization angle of incident light; therefore, the transmittance at resonant frequencies was increased while the polarization angle varied from 0 to 180 degree. These high-performance plasmonic modulators have emerging potential for the design of optical buffers, slow light devices, multistop band filters, integrated photonic circuits, and various optoelectronic systems.