Tunable multi-resonance of terahertz metamaterial using split-disk resonators

Daoye Zheng,Xingzhuo Hu,Chang-Han Chen,Yu-Sheng Lin

doi:10.1063/1.5139263

Abstract

We present three tunable multi-resonance of terahertz (THz) metamaterials. They are composed of single-, dual-, and triple-split-disk resonators (SDRs) on Si substrates, which are denoted as SDR-1, SDR-2, and SDR-3, respectively. They exhibit extraordinary electromagnetic characteristics. SDR-1 exhibits polarization-dependence owing to the asymmetrical SDR structure. To increase the flexibility and applicability of SDR configuration, SDR-2 and SDR-3 are presented to modify the distances between the SDR layers. By moving the top SDR layer of SDR-2, a controllable resonance with a 0.32 THz shifting and tunable free spectrum range (FSR) of 0.15 THz at transverse magnetic mode is achieved, while an electromagnetically induced transparency-like effect appears at the transverse electric mode. The spectral bandwidth of SDR-3 can be tuned to 0.10 THz, and the resonant intensity becomes controllable by moving the middle SDR layer of SDR-3. Furthermore, by moving the top SDR layer of SDR-3, the tuning ranges of resonance, FSR, and bandwidth of SDR-3 are 0.23 THz, 0.20 THz, and 0.08 THz, respectively. Such designs of SDR configurations provide a high-efficient THz resonator in the THz-wave applications such as filters, switches, polarizers, sensors, imaging, and so on.

Highlights

Terahertz (THz) wave is the electromagnetic spectrum between the microwave and infrared wavelength range
At transverse magnetic (TM) mode, there is single-resonance at 0.52 THz, as shown in Fig. 2(a), which is generated by one inductive element within split-disk resonators (SDRs)-1 as the E- and H-field distributions shown in Figs. 2(d) and 2(e), respectively
We present a high-efficient design of tunable THz metamaterial to tune the resonance, free spectrum range (FSR), and bandwidth by using SDR layers. These results show that these are single, dual, and triple-resonances depending on polarization and the specific design of SDRs at TM mode

Summary

Introduction

Terahertz (THz) wave is the electromagnetic spectrum between the microwave and infrared wavelength range. It is a hot technique topic and is hopefully to be widely employed in various applications including but not limited to semi-conductor lasers, imaging, detectors, sensors, and radars.[1–9] The major drawback of the THz wave is the lack of high-efficient interaction coupling with the device because the THz wave has high transmission in common plastics, insulation materials, woods, and rubbers, and high reflection for metals.[10]. These traditional materials cannot be interacted well with the THz wave, which will impede the practical applications of the THz wave technique. According to the theory of the Drude–Lorentz model, the characteristics of the incident electromagnetic wave could be interacted and controlled by the metamaterial configurations.[15,16] Many literature studies have been reported for diversified metamaterials based on the configuration of the split-ring resonator (SRR).[17–25] The variations of SRR configurations include V-shaped SRR,[17,18] C-shaped SRR,[19] Ushaped SRR,[20–22] and three-dimensional (3D) SRR.[23,24] they can combine with two-dimensional materials (such as graphene),[25–30] phase change materials,[31] super conductors,[32,33] and semiconductors.[34]

Methods

Results

Conclusion