Terahertz multiband ultrahigh index metamaterials by bilayer metallic grating structure
- 76 Downloads
One-dimensional metallic grating structure was proposed to realize high refractive index metamaterial in the terahertz region. By drastically increasing the effective permittivity by means of intense capacitive coupling and reducing the diamagnetic effect using a thin metallic thickness, a peak refractive index of 15.81 at the resonant frequency in embedded metallic grating can be obtained. Multiband high refractive index metamaterial can be realized by double symmetric metallic grating and asymmetric grating structure. For asymmetric grating metamaterial structure, two separate transmission peaks appear and result in two separate high refractive index. Interestingly, a near zero refractive index metamaterial can be obtained by the introduction of double asymmetric design. It was found that our designed ultrahigh refractive index metamaterials depend on the electric field coupling effect and the magnetic field diamagnetic response.
The authors acknowledge the support from Natural Science Foundation of Zhejiang Province (LY17F050009, LQ15F050004), National Natural Science Foundation of China (NSFC) (No.61505192).
- 5.R. Singh, W. Singh, W. Zhang, Ultra-high terahertz index in deep subwavelength coupled bi-layer free-standing flexible metamaterials. J. Appl. Phys. 121.23:2075–329 (2017)Google Scholar
- 7.K. Ishihara, T. Suzuki, Metamaterial demonstrates both a high refractive index and extremely low reflection in the 0.3-THz Band. J. Infrared Millimeter Terahertz Waves, 1–10 (2017)Google Scholar
- 12.J.B. Pendry., D. Schurig, D.R. Smith, J.B. Pendry, D. Schurig, Smith, D. R, Controlling electromagnetic fields. Science 312, 1780–1782, Science, 312(5781), p. 1780–1782. (2006)Google Scholar
- 17.S.C.A. Sonsilphong, N. Wongkasem, “Meta-materials with near-zero refractive index produced using fishnet structures. J. Opt. 16.1, 100–103 (2013)Google Scholar
- 21.R. Vukoman, ČolovićB. Jokanović, Miloš Nenadovič, Anka Trajkovska Petkovska, Mitrić. M, & B. Jokanović, Ultra-high and near-zero refractive indices of magnetron sputtered thin-film metamaterials based on TixOy. Adv. Mater. Sci. Eng., 7–8 (2016)Google Scholar
- 22.Z. Lu, B. Campsraga, N.E. Islam, Design and Analysis of a THz metamaterial structure with high refractive index at two frequencies. Physics Research International, pp. 2090–2220 (2012)Google Scholar
- 30.X.R. Shi., Y. Guo., R. Chen., T. Hao. L, & Chen, X, Periodic structural defects in Bragg gratings and their application in multiwavelength devices. Photonics Res., 4.2:35 (2016)Google Scholar