Numerical investigation of terahertz polarization-independent multiband ultrahigh refractive index metamaterial by bilayer metallic rectangular ring structure

Fang, Bo; Chen, Lin; Deng, Yuqiang; Jing, Xufeng; Li, Xue

doi:10.1039/c8ra03758b

Cited by 9 publications

(5 citation statements)

References 20 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Also, we should comment that effective parameters of the metasurface including permittivity, permeability and refractive index can be in-principle retrieved from scattering parameters ( and ) 34 . This retrieval method is quite widely used to extract effective parameters even for higher refractive index materials as seen in literature 43 – 45 ; however, it should be noted that different retrieval methods and their implementation can lead to inconsistent data which violates Krammers–Kronig relations 46 .…”

Section: Electromagnetic Response and Field Profilesmentioning

confidence: 99%

Collective photonic response of high refractive index dielectric metasurfaces

Amanaganti

Ravnik

Dontabhaktuni

2020

Sci Rep

View full text Add to dashboard Cite

Sub-wavelength periodic nanostructures give rise to interesting optical phenomena like effective refractive index, perfect absorption, cloaking, etc. However, such structures are usually metallic which results in high dissipative losses and limitations for use; therefore, dielectric nanostructures are increasingly considered as a strong alternative to plasmonic (metallic) materials. In this work, we show light-matter interaction in a high refractive index dielectric metasurface consisting of an array of cubic dielectric nano-structures made of very high refractive index material, Te in air, using computer modelling. We observe a distinct band-like structure in both transmission and reflection spectra resulting from the near-field coupling of the field modes from neighboring dielectric structures followed by a sharp peak in the transmission at higher frequencies. From the spatial distribution of the electric and magnetic fields and a detailed multipole analysis in both spherical harmonics and Cartesian components, the dominant resonant modes are identified to be electric and magnetic dipoles. Specifically at lower frequency (60 THz) a novel anapole-like state characterized by strong-suppression in reflection and absorption is observed, reported very recently as ‘lattice-invisibility’ state. Differently, at higher frequency (62 THz), strong absorption and near-zero far field scattering are observed, which combined with the field profiles and the multipole analysis of the near-fields indicate the excitation of an anapole. Notably the observed novel modes occur in the simple geometry of dielectric cubes and are a result of collective response of the metasurfaces. Periodicity of the cubic metasurface is shown as the significant material tuning parameter, allowing for the near-field and far-field coupling effects of anapole metasurface. More generally, our work is a contribution towards developing far-fetching applications based on metamaterials such as integrated devices and waveguides consisting of non-radiating modes.

show abstract

Section: Electromagnetic Response and Field Profilesmentioning

confidence: 99%

Collective photonic response of high refractive index dielectric metasurfaces

Amanaganti

Ravnik

Dontabhaktuni

2020

Sci Rep

View full text Add to dashboard Cite

show abstract

“…This can be attributed to the impedance-matching effect, which is used to explain the physical mechanism of the absorption properties for broadband absorbers. The relative impedance can be expressed as [44]:…”

Section: Resultsmentioning

confidence: 99%

“…physical mechanism of the absorption properties for broadband absorbers. The relative impedance can be expressed as [44]:…”

mentioning

confidence: 99%

Patterned Graphene-Based Metamaterials for Terahertz Wave Absorption

Zhou

et al. 2022

Coatings

View full text Add to dashboard Cite

Graphene-based metamaterials have been widely applied in optoelectronic devices, optical modulators, and chemical sensors due to the outstanding tunability and optical response in the terahertz (THz) region. Here, tunable THz metamaterial absorbers based on patterned graphene are designed, fabricated, and modulated. The proposed metamaterial absorbers are constructed by the top layer of patterned graphene arrays and the aluminum (Al) film separated by polyimide (PI). The different THz absorption spectra can be acquired by changing the patterns of graphene. In order to verify the simulation results, a series of tests were conducted by THz time-domain spectrometer (THz-TDS) systems. The proposed absorbers are able to be insensitive to the angle of the incident wave. Besides, chemical doping is applied to turn the Fermi level of graphene and the absorption performance is promoted with the increase of the Fermi level. The experimental results have been demonstrated to have associated resonant peaks with the simulation results. The aim of this paper is to exhibit a systematic study on graphene-based THz metamaterial absorbers, including the simulation and experiments. By comparing the simulation and experimental results, it is useful to clarify the relevant theories and manufacturing processes. The work will provide a further step in the development of high-performance terahertz devices, including tunable absorbers, sensors, and electro-optic switches.

show abstract

“…Flat optics based on metasurfaces [22][23][24][25][26] makes it possible to replace three-dimensional massive optical components with two-dimensional optically thin components and would be a welcome contribution to cover the terahertz gap. High refractive index metasurfaces [27][28][29][30][31][32][33][34][35][36][37] have offered artificial materials suitable for terahertz flat optics. Metasurfaces with high refractive indices [27][28][29][30][31][32][33][34] are subject to high Fresnel reflections due to the control of only the permittivity.…”

mentioning

confidence: 99%

“…High refractive index metasurfaces [27][28][29][30][31][32][33][34][35][36][37] have offered artificial materials suitable for terahertz flat optics. Metasurfaces with high refractive indices [27][28][29][30][31][32][33][34] are subject to high Fresnel reflections due to the control of only the permittivity. Lowreflection properties are required to integrate two-dimensional planar optical components based on flat optics with terahertz CW sources.…”

mentioning

confidence: 99%

Resonant tunneling diode integrated with metalens for high-directivity terahertz waves

Endo

Sekiya

Sato

et al. 2021

Appl. Phys. Express

View full text Add to dashboard Cite

Terahertz flat optics based on our originally developed low-reflection metasurface with a high refractive index can offer attractive two-dimensional optical components for the manipulation of terahertz waves. However, it remains to be shown whether a planar collimating metalens made with our original metasurface could be mounted on a resonant tunneling diode with a short distance. Here, we demonstrate that a collimating metalens with a distance of 1.0 mm from the RTD enhances the directivity to 3.0 times at 0.312 THz. The proposed metalens would be integrated with various terahertz continuous-wave sources for emerging industry such as 6 G (beyond 5 G) communications.

show abstract

Numerical investigation of terahertz polarization-independent multiband ultrahigh refractive index metamaterial by bilayer metallic rectangular ring structure

Abstract: Multiband high index of refraction can be realized by thin ring-type terahertz metamaterials composed of multilayer coupled unit cells.

Cited by 9 publications

References 20 publications

Collective photonic response of high refractive index dielectric metasurfaces

Collective photonic response of high refractive index dielectric metasurfaces

Patterned Graphene-Based Metamaterials for Terahertz Wave Absorption

Resonant tunneling diode integrated with metalens for high-directivity terahertz waves

Contact Info

Product

Resources

About