Terahertz functional devices have been instrumental in the development of terahertz technology. Moreover, the advent of metamaterials has greatly contributed to the advancement of terahertz devices. However, most of today's metamaterials in the terahertz band exhibit poor performance and are mono-functional. This greatly limits the scalability and application potential of the devices. To achieve diversification and tunability of device functionality, we propose a combination of metamaterial structures and vanadium dioxide film. A metamaterial absorber based on the thermotropic phase change material VO2 has been designed. Flexible switching of absorption performance (complete reflection and ultra-broadband perfect absorption) can be achieved through temperature adjustment. Moreover, the perfectly absorbed bandwidth is a staggering 3.3 THz. The thermal tuning of spectral absorbance has a maximal range of 0.01 to 0.999. The shift in absorption properties is explained by the phase change process of vanadium oxide (MIT). The electric field intensity on the absorber surface at different temperatures was monitored and analysed as a way to correlate the VO2 film phase transition process. The impedance matching theory is applied to explain the high level of absorption generated by the absorber. Finally, the effects of the structural parameters on the performance of the absorber are analysed. This work will have many applications in the terahertz field and offers a wide range of ideas for the design of terahertz-enabled devices. 

A switchable terahertz device combining ultra-wideband absorption and ultra-wideband complete reflection

In this paper, we design a polarization-independent and angle-insensitive broadband THz graphene metamaterial absorber based on the surface plasmon-polaritons resonance. Full-wave simulation is conducted, and the results show that the designed metamaterial absorber has an absorption above 99% in the frequency range from 1.23 THz to 1.68 THz, which refers to a very high standard. Furthermore, the absorber has the properties of tunability, and the absorption can be nearly adjusted from 1% to 99% by varying the Fermi energy level of the graphene from 0 eV to 0.7 eV. In the simulation, when the incident angles of TE and TM waves change from 0° to 60°, the average absorption keeps greater than 80%. The proposed absorber shows promising performance, which has potential applications in developing graphene-based terahertz energy harvesting and thermal emission.

Tunable polarization-independent and angle-insensitive broadband terahertz absorber with graphene metamaterials.

In this paper, for improving the refractive index sensitivity, we propose different sensor devices by optical metamaterial nanoabsorbers. The presented absorbers are designed by different configurations such as basic model, nanorods, and nanotube array. With three-dimensional finite difference time domain (FDTD) method, their absorption, transmission, and reflection spectra, and sensitivity and figure of merit (FOM) values are numerically investigated. The simulation results show that the resonances at longer wavelengths have higher values of sensitivity and FOM. For presenting the applicability, we examine the sensor for detecting cancerous cells. The proposed absorbers have been coated with an outer material with a thickness of 100 nm and refractive indices of 1 ⁓ 1.2. The maximum sensitivity is obtained at 1055 nm/RIU for the absorber with nanotube array, while its FOM is 19.5 RIU−1. Due to its spectral characteristics, the proposed structures can be used to detect other materials such as human blood group, ethanol, and hemoglobin concentrations of some materials.

Tunable and Sensitive Refractive Index Sensors by Plasmonic Absorbers with Circular Arrays of Nanorods and Nanotubes for Detecting Cancerous Cells

A wideband and polarization-insensitive graphene-based metamaterial absorber

Achieving ultra-broadband and completely modulated absorption enhancement of monolayer graphene in near-infrared region is practically important to design graphene-based optoelectronic devices, however, which remains a challenge. In this work, by spectrally designing multiple magnetic plasmon resonance modes in metamaterials to be adjacent to each other, near-infrared light absorption in monolayer graphene is greatly improved to have an averaged absorption efficiency exceeding 50% in a very broad absorption bandwidth of about 800 nm. Moreover, by exerting an external bias voltage on graphene to change Fermi energy of graphene, the ultra-broadband absorption enhancement of monolayer graphene exhibits an excellent tunability, which has a nearly 100% modulation depth and an electrical switching property. This work is promising for applications in near-infrared photodetectors, amplitude modulators of electromagnetic waves, etc.

Ultra-broadband and completely modulated absorption enhancement of monolayer graphene in a near-infrared region.

We propose an ultraviolet perfect ultranarrow band absorber by coating a dielectric grating on the monolayer graphene-dielectric-metal structure. The absorber presents an ultranarrow Fano lineshape with quality (Q) factor of 70 and a nearly perfect absorption of over 99.9% in the ultraviolet region, which is ascribed to the near field coupling of the optical dissipation of graphene and guide mode resonance of the dielectric grating. Structure parameters to the influence of the performance are investigated. The structure exhibits the high optical sensitivity (S = 150 nm/RIU, S* = 48/RIU) and figure of merit (FOM = 50, FOM* = 25374) and can also be used to detect the nanoscale analyte layer of sub-nanometer thickness, suggesting great potential applications in ultra-compact efficient biosensors for a much more sensitive detection of small refractive index changes.

Graphene ultraviolet ultrahigh-Q perfect absorption for nanoscale optical sensing.

We numerically investigate the multipolar plasmonic resonances of Aluminum nanoantenna tuned by a monolayer graphene from ultraviolet (UV) to visible regime. It is shown that the absorbance of the plasmonic odd modes (l = 1 and l = 3) of graphene–Al nanoribbon structure is enhanced while the absorption at the plasmonic even modes (l = 2) is suppressed, compared to the pure Al nanoribbon structure. With the presence of the monolayer graphene, a change in the resonance strength of the multipolar plasmonic modes results from the near field interactions of the monolayer graphene with the electric fields of the multipolar plasmonic resonances of the Al resonator. In particular, a clear absorption peak with a high quality (Q)-factor of 27 of the plasmonic third-order mode (l = 3) is realized in the graphene–Al nanoribbon structure. The sensitivity and figure of merit of the plasmonic third-order mode of the proposed Graphene–Al nanoribbon structure can reach 25 nm/RIU and 3, respectively, providing potential applications in optical refractive-index sensing.

Multipolar Plasmonic Resonances of Aluminum Nanoantenna Tuned by Graphene.

Graphene hybridized ultrahigh-Q high-order Fano resonance for nanoscale optical sensing

We theoreticallydemonstrate the realization of the ultranarrow dual-band perfect absorption at visible range in 3D metamaterials comprising Au vertical split-ring resonators (VSRRs) array above a thick Au film for high-sensitivity sensing. By placing the 3D metamaterial of Au VSRRs directly onto the Au substrate to remove the dielectric substrates effect, the simulated results reveal that ultranarrow dual-band perfect absorption with the two narrow absorption bandwidth of 7.3 nm and 1.1 nm in the visible regime can be excited from pure magnetic plasmon (MP) resonance and via the strong coupling between the MP resonance of the VSRRs and the surface plasmons polaritons (SPPs) propagating on the Au film, respectively. Moreover, coupling effects in the VSRRs with different structural parameters also are studied in detail. Because of the ultranarrow dual-band perfect absorption of the VSRRs being extremely sensitive to the changes of the material surrounding, our proposed 3D metamaterial exhibits ultrahigh sensitivity ( S = 918 nm/RIU, S * = 680/RIU) and figure of merit ( FoM = 835, FoM * = 4.5×106) in near-infrared regime, which hold potential applications in label-free biosensing.

Ultranarrow Dual-Band Perfect Absorption in Visible and Near-infrared Regimes Based on Three-Dimensional Metamaterials for Ultrahigh-Sensitivity Sensing

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.

Xingting Pu

Author Tools

Chat about Author

Papers

Graphene ultraviolet ultrahigh-Q perfect absorption for nanoscale optical sensing.

Multipolar Plasmonic Resonances of Aluminum Nanoantenna Tuned by Graphene.

Graphene hybridized ultrahigh-Q high-order Fano resonance for nanoscale optical sensing

Ultranarrow Dual-Band Perfect Absorption in Visible and Near-infrared Regimes Based on Three-Dimensional Metamaterials for Ultrahigh-Sensitivity Sensing