Using some special properties of a permeability-near-zero material, the radiation of a line current is greatly enhanced by choosing appropriately the dimension of a dielectric domain in which the source lies and that of a permeability-near-zero shell. The radiation of the source can also be completely suppressed by adding appropriately another dielectric domain or an arbitrary perfect electric conductor (PEC) inside the shell. Enhanced directive radiation is also demonstrated by adding a PEC substrate.

Enhancing and suppressing radiation with some permeability-near-zero structures

An ultrathin planar cavity metasurface is proposed based on ultrathin film interference and its practicability for light manipulation in visible region is experimentally demonstrated. Phase of reflected light is modulated by finely adjusting the thickness of amorphous silicon (a-Si) by a few nanometers on an aluminum (Al) substrate via nontrivial phase shifts at the interfaces and interference of multireflections generated from the planar cavity. A phase shift of π, the basic requirement for two-level phase metasurface systems, can be accomplished with an 8 nm thick difference. For proof of concept, gradient metasurfaces for beam deflection, Fresnel zone plate metalens for light focusing, and metaholograms for image reconstruction are presented, demonstrating polarization-independent and broadband characteristics. This novel mechanism for phase modulation with ultrathin planar cavity provides diverse routes to construct advanced flat optical devices with versatile applications.

Ultrathin Planar Cavity Metasurfaces

We numerically validate and experimentally realize considerable funneling of electromagnetic energy through a subwavelength aperture that is covered with an epsilon-near-zero metamaterial (ENZ). The epsilon-near-zero metamaterial is composed of two layers of metasurfaces and operates at microwave frequencies. We demonstrate that the presence of the metamaterial at the inner and outer sides of the aperture not only lead to a significant enhancement in light transmission, but also cause a directional emission of light extracting from this hybrid system. In addition to these experimental results, we theoretically demonstrate the same concept in mid-IR region for a subwavelength gold aperture with indium tin oxide as an epsilon-near-zero material. Moreover, we found that using a dielectric spacer in-between the sunwavelength aperture and the ENZ medium, it is possible to red-shift the enhancement/directional frequency of the system.

/pdf/beaming-and-enhanced-transmission-through-a-subwavelength-2x12w2n13c.pdf

Beaming and enhanced transmission through a subwavelength aperture via epsilon-near-zero media.

This paper presents a zero metamaterial (ZIM) structure for the gain and directivity reinforcement of the TSA. The designed ZIM cell, which consists of resonant metal structure and inductor component, can operate at low frequencies with one component of permittivity tensor reaching zero. By changing the inductance value of the inductor component, the zero point of permittivity tensor of the ZIM will shift correspondingly. We embed ZIM cells in the typical TSA to improve the gain and directivity of TSA, making the overall structure compact, and the embedded ZIM cells have no effect on the operating frequency band of the TSA. The simulated results indicate that the gain of the TSA loaded with the ZIM cells has been enhanced by 0.9–2.48 dB, and the half-power beam width has been decreased by least 10° in the frequency range of 0.575–0.590 GHz compared with typical TSA. The measured results are well consistent with the simulated ones. The new designed antenna can be applied in the grounded-penetrating...

A zero-index metamaterial for gain and directivity enhancement of tapered slot antenna

In this work, we design a heterojunction in a two dimensional parallel-plate metallic waveguide by using zero-index metamaterials and anisotropic dielectrics which are electrically tunable. We show analytically and numerically that by only controlling the direct current voltage applied to the anisotropic dielectrics, the phenomena of perfect transmission and near perfect reflection can be tuned electrically. Such designed junctions can service as electrically tunable switches in waveguide systems, with good performances and high sensitivities. Our work provides another way to electrically control the propagation of electromagnetic waves in waveguide systems.

Electrically tunable electromagnetic switches based on zero-index metamaterials

In this work, we theoretically investigate the transmission effect of electromagnetic wave in a waveguide structure with a dielectric slit of a sub-wavelength width, on both sides of which zero index metamaterials (ZIMs) are placed. We show that the transmittance in such a waveguide structure can increase considerably due to the squeezing function of ZIMs. In particular, total transmission can be achieved when the Fabry–Perot resonance condition is satisfied by adjusting the material properties of the dielectric filled in the slit. Numerical simulations agree well with analytic results. Because the media filled in the sub-wavelength slit are not necessarily ZIMs but just normal dielectrics, our work greatly reduces the difficulty for implementation.

https://iopscience.iop.org/article/10.1088/2040-8978/17/10/105602/pdf

Total transmission through a sub-wavelength slit based on Fabry–Pérot resonance and zero-index metamaterials

Handle everyday research tasks with reliable, citation-backed results

Your personal Research Agent to handle research tasks with citation-backed results

Popular Tasks used by Researchers

How can I help with your research?

Meet SciSpace

Get more enhanced response by uploading the PDFs you want me to reference.

No relevant PDFs in your library

SciSpace is the AI research assistant for academics. Run systematic literature reviews on 280M+ papers, and write papers with cited sources. Trusted by 1M+ students, PhDs & researchers.

SciSpace | AI for Research

Analyze PDFs

Code & Manuscripts

Funding & Grants

Literature & Patents

Medical & Clinical Data

Systematic Review

Visualize & Present

Web & Data

Build a Google Scholar-like website for your research.

Build a website

Create charts and images for your research

Create a Chart

Write a paper for submission to a journal

Draft a manuscript

Patent Search

Design eye-catching scientific posters in minutes.

Scientific Poster Generation

Systematic Literature Review

One task is running at the moment. Your messages will be shown right after.

Drag and drop or click here to browse

Loved by <highlight>1 million+</highlight> researchers

Extract a list of specific topics and their sources from unstructured text

Topics

Compare and analyze relevant papers that matches with your search

Papers

Get insights from PDFs and bookmarked papers from your library

My library

Recent searches

Try searching for:

Catch AI-generated content in scholarly and non-scholarly content

{ai} Detector

Ai Writer

Get PDF Summaries, highlighted text explanations 

Chat with PDF

Effortlessly create in-text citations and bibliographies in APA and 2,500 other formats

Citation generator

Get explanations, summaries, and answers on academic papers

Ease up your research workflow with {scispace}'s cohort of exciting AI tools

Elevate your academic writing skills and convey your ideas the way you want

Paraphraser

Explore our range of reading and writing tools

Your file is being prepared and should be ready in a few minutes. If it's a large file, it might take a bit longer. You can close this window, and we'll email you the file when it's done.

You have reached a maximum limit of <strong>{limit}</strong> columns in the table. Remove at least <strong>1</strong> column to add or create another one.

Aichen Chen

Author Tools

Chat about Author

Papers

Total transmission through a sub-wavelength slit based on Fabry–Pérot resonance and zero-index metamaterials