Terahertz broadband metamaterial absorber enabled by $$\hbox {SiO}_{{{2}}}$$ SiO 2 ,
- PDF / 4,833,380 Bytes
- 6 Pages / 595.276 x 790.866 pts Page_size
- 99 Downloads / 187 Views
© Indian Academy of Sciences
Terahertz broadband metamaterial absorber enabled by SiO2 , polyimide and PET dielectric substrates A ELAKKIYA1,∗ , S RADHA1 , B S SREEJA1 and E MANIKANDAN2 1 Department
of ECE, SSN College of Engineering, SSN Nagar, Kalavakkam, Chennai 603 110, India of ECE, School of SENSE, VIT Chennai Campus, Rajan Nagar, Chennai 600048, India ∗ Corresponding author. E-mail: [email protected] 2 Department
MS received 6 November 2019; revised 5 June 2020; accepted 1 July 2020 Abstract. A broadband polarisation-insensitive terahertz (THz) metamaterial absorber (MMA) is presented in this paper. The MMA consists of a simple planar structure as a unit cell and an optically transparent indium tin oxide (ITO) ground plane, both are separated by a 50 μm dielectric substrate. We designed three combinations of MMA here, which are ITO–polyimide–ITO, ITO–polyethylene terephthalate (PET)–ITO and ITO–silicon dioxide (SiO2 )– ITO for the same planar structure. By changing the substrate of the structure, the resonant frequency and bandwidth of the absorber structure can be varied. The numerical simulation of the absorber shows that the absorptivity is >96% for all three substrates. Polyimide, PET and SiO2 based absorbers demonstrated the bandwidth of 0.558 THz, 0.603 THz and 0.658 THz with covered broadband frequency range of 0.4254–0.9829 THz, 0.457–1.16 THz and 0.511–1.169 THz respectively. ITO–PET–ITO absorber structure produced optical transparency. These bandwidths are compatible and convenient for electronic sources in the terahertz region. This study also provides applications in THz sensing and imaging, communication and detection systems. Keywords. Polyimide; silicon dioxide; polyethylene terephthalate; optical transparency; broadband. PACS Nos 81.05.Xj; 78.67.Pt; 87.50.U
1. Introduction Research on terahertz (THz) technology is getting attention from many researchers around the world due to its applications in different fields. Terahertz band lies between the microwaves and infrared waves within the frequency range of 0.1–10 THz [1]. Metamaterials are artificial materials engineered to provide properties such as perfect lensing [2], invisibility [3], negative refractive index [4], cross polarisation conversion [5], perfect absorption [6] and asymmetric transmission [7], which are not readily available in nature. These materials get their properties from the structure rather than composition. Because of their unique properties, metamaterials become excellent electromagnetic wave absorbers. To manipulate the electromagnetic waves from microwaves to visible regime, different types of metamaterial filters [8], multiband metamaterial absorbers [9], broadband metamaterial absorbers [10] and cloak [11] have been demonstrated. The first metamaterial was proposed by Landy et al in the year 2008. The proposed metamaterial consisted of a 0123456789().: V,-vol
split ring resonator and metallic cut wires and when a dielectric sheet is placed between them, it achieved single-point absorption [12]. After this, many
Data Loading...
