Optimization of strip-based hybrid plasmonic terahertz waveguide with distributed Bragg reflector layers

Abstract

In view of recent developments in the utilization of terahertz (THz) communications technology for the increasing demands of high speed and data rates for various wireless applications, this research work targets the design and analysis of distributed Bragg reflector (DBR)based hybrid plasmonic THz waveguide. This THz waveguide operates at a frequency range from 2.5 to 3.5 THz. The proposed DBR-based hybrid plasmonic THz waveguide consists of DBR layers of gallium arsenide (GaAs) and aluminum arsenide, high-density polyethylene (HDPE) as substrate, a GaAs stripe for wave-guidance, and few layers of graphene layers in HDPE for better confinement. To increase the light confinement between DBR and graphene, a GaAs strip is placed into HDPE. By altering the width and height of the GaAs strip, the parameters birefringence, mode field diameter (MFD), confinement loss, effective mode area, beat length, and dispersion have been fully examined. The obtained simulation results shows high birefringence of 0.6276, maximum MFD of 45 mm, low confinement loss of 7.5 × 10 −9 mm −1 , high effective mode area of 16.5 mm 2 , and low anomalous dispersion of 0.0023 (ps/THz/cm) in the range of 2.5 to 3.5 THz. This optimized THz waveguide may helps to enable in guided THz applications for photonic integrated circuits.

WITHDRAWN: Performance Analysis of Hybrid Plasmonic Terahertz Waveguide fed Patch Antenna

“…The width and height of the patch layers are represented by W and L. To minimize the reflection, the patch antenna is constructed to have an input impedance is equal to the wave impedance of the waveguide fed. The refractive index of material GaAs, AlAs, HDPE are 3.31, 2.87, and 1.54 respectively for a frequency of 2.5 to 3.5 [18,[22][23][24]. The parametric list for the designed hybrid plasmonic THz waveguide-fed patch antenna is described in Table 1.…”

“…where ω τ = 2.733 x 10 13 rad/s is the damping frequency and ω p = 1.37 x 10 16 rad/s is the plasma frequency in THz frequencies [15,25]. Additionally, graphene conductivity can be determined by using Kubo's formula [18,26], written as…”

“…where fd is the Fermi-Dirac distribution, due to the intraband scattering the fd can be written as [18,26],…”

“…Here, µc is the chemical potential, τ is the momentum relaxation time, ε is the energy and T is the temperature, ℏ denotes reduced Planck's constant. The intraband electron-photon scattering mechanism is explained by the first term [18,26] in equation ( 2)…”

“…However, the performance of the waveguide-fed antenna is greatly influenced by the material selection and structural dimensions. In this research work, GaAs is chosen which is one of the least absorbing electro-optic crystals at THz frequency (with an absorption coefficient 5 cm −1 below 3 THz) and has numerous advantages that make it a good candidate for THz generation, large thermal conductivity, and fabrication techniques [17,18]. Further, High-density polyethylene with the absorption of <0.4 cm −1 has lower loss compared with other polymer materials like polymethyl methacrylate (PMMA) and PC (polycarbonate) [19,20].…”