A Wide Incident Angle, Ultrathin, Polarization-Insensitive Metamaterial Absorber for Optical Wavelength Applications

Sultan Mahmud,Sikder Sunbeam Islam,Mohammad Tariqul Islam,Ali F Almutairi

doi:10.1109/access.2020.3008429

Abstract

Polarization-insensitive metamaterial absorbers (MMAs) are currently attracting a great deal of interest throughout the optical region. These kinds of MMAs can be used as energy harvesting, thermal imaging, plasmonic sensor, magnetic imaging, light trapping, optical modulator, and can help to decipher an inherence for the field. Here, a polarization-insensitive ultrathin MMA has been proposed with an extensive incident angular stability for the optical region with a sandwiched three-layer structure. Tungsten (W) and silicon dioxide (SiO2) have been chosen as materials for their various advantages in the optical spectrum with higher temperature stability. The design simulated with the finite integration technique (FIT), and validation of the simulated data is assured with the interference theory model (ITM). Underlying physics of the absorption characteristics and performance of the structure are immensely explained. The design acquired an average absorption of 96.7% from 380nm to 700nm and 96.61% for both transverse electric (TE) and transverse magnetic (TM) polarization. It has a peak absorption of 99.99% at 498.25nm, and over 99% from 460nm to 540nm, due to a very good impedance match with plasmonic resonance characteristics. For both TE and TM mode, it has wide angular independence up to 60°, which can be used for solar cell and solar thermo-photovoltaics (STPV). The various parametric sweep also analyzed for acquiring the geometric shape with a wide bandwidth to find resonance wavelength. As the MMA shifts its resonance wavelength with the change of its dielectric thickness, it can be used as an optical sensor. Changing dielectric in a Pyrex will enable the structure to be used as a light detector. Such outstanding absorption properties render the proposed MMA a successful candidate for the optical wavelength applications mentioned above.

Highlights

FOR CALCULATION OF ABSORBANCE For calculation of absorbance, scattering parameters (S-parameter) are extracted by the Nicolson–Ross–Weir (NRW) method discussed in reference [101]
As absorbance is highly dependent on the impedance match, the impedance of the unit cell Z (ω) = {μr (ω).μ0/[εr (ω).ε0]}1/2 and characteristic impedance Z0 = (μ0/εr )1/2 = 376.73 ≈ 377
The structure is symmetrical, but to clinch the matter, we demonstrated both co-polarization and cross-polarization components in Fig. 4(a) with the help of (3) and (4)

Summary

Introduction

Veselago devotee Smith et al to find an artificial double negative (DNG) metamaterial with negative permeability and permittivity [1], [2]. These proper-ties of metamaterials depends on their physical structure that enables them to be used as antennas [3], waveguides [4], filters [5], invisible cloaks [6], absorbers [7], [8], The associate editor coordinating the review of this manuscript and approving it for publication was Santi C. After the first corroboration of metamaterial absorbers (MMA) in 2008 by Landy et al, they have been studied vigorously, both theoretically and practically [20].

Methods

Results

Conclusion