Browse
Submit Data
Databases
API
Help

Dataset Information

28 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Manipulation of the polarization of Terahertz wave in subwavelength regime.

ABSTRACT: By generalizing the concept of spoof surface Plasmons (Science 305, 847), we analytically demonstrate that subwavelength quarter-wave and half-wave plates can be realized in a metal hole array (MHA) sandwiched by two thin-layer materials, whose optical responses can be characterized by their optical conductivities. These abilities of polarization conversion can be attributed to the novel eigenstates induced by the hybridization of the spoof surface plamsons with the current generated in the thin-layer. Due to this mechanism, the robustness of the system is promised. The analytic predictions are verified numerically by modeling the thin-layer material as an experimentally feasible topological-insulator/SiO2 multilayer. Moreover, the possibility of extending the principle to a broad range of materials is dicussed.

SUBMITTER: Xiao X

PROVIDER: S-EPMC4319153 | biostudies-literature | 2015 Feb

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Publications

Manipulation of the polarization of Terahertz wave in subwavelength regime.

Xiao Xiao X Leung Ho Ming HM Chan C T CT Wen Weijia W

Scientific reports 20150206

By generalizing the concept of spoof surface Plasmons (Science 305, 847), we analytically demonstrate that subwavelength quarter-wave and half-wave plates can be realized in a metal hole array (MHA) sandwiched by two thin-layer materials, whose optical responses can be characterized by their optical conductivities. These abilities of polarization conversion can be attributed to the novel eigenstates induced by the hybridization of the spoof surface plamsons with the current generated in the thin ...[more]

PMID: 25655196

Similar Datasets

Magnetic-control multifunctional acoustic metasurface for reflected wave manipulation at deep subwavelength scale.

Project description:Acoustic metasurfaces, exhibiting superior performance with subwavelength thickness, are ideal alternatives for functionalities such as wavefront modulation and acoustic energy trapping, etc. However, most of the reported acoustic metasurfaces were passive. Here a magnetically tuned mechanism is reported for membrane-type acoustic metamaterials. Harnessing the geometric nonlinearity of membrane structures, the transmission spectrum is both theoretically and experimentally tuned over broadband by an external static magnetic force. Simultaneously, the phase profiles can be readily tailored by the magnetic stimulus. Further, a magnetic-control multifunctional metasurface is proposed for low-frequency wave manipulation. By switching the magnetic force distribution, multi extraordinary phenomena, such as acoustic wave redirecting, focusing, bending, etc., are realized without changing the physical structure. Besides, it is demonstrated the proposed metasurface, at deep subwavelength scale (~1/85?), supports anomalous reflected wave manipulation over a wide band. These results open up new degrees of freedom to steer acoustic wave and pave a way for designing active acoustic devices.

| S-EPMC5567380 | biostudies-literature

Subwavelength Terahertz Imaging of Graphene Photoconductivity.

Project description:Using a spatially structured, optical pump pulse with a terahertz (THz) probe pulse, we are able to determine spatial variations of the ultrafast THz photoconductivity with subwavelength resolution (75 ?m ? ?/5 at 0.8 THz) in a planar graphene sample. We compare our results to Raman spectroscopy and correlate the existence of the spatial inhomogeneities between the two measurements. We find a strong correlation with inhomogeneity in electron density. This demonstrates the importance of eliminating inhomogeneities in doping density during CVD growth and fabrication for photoconductive devices.

| S-EPMC5115732 | biostudies-literature

Subwavelength polarization optics via individual and coupled helical traveling-wave nanoantennas.

Project description:Light polarization control is a key factor in modern photonics. Recent advances in surface plasmon manipulation have introduced the prospect of more compact and more efficient devices for this purpose. However, the current plasmonic-based polarization optics remain much larger than the wavelength of light, which limits the design degrees of freedom. Here, we present a plasmonic traveling-wave nanoantenna using a gold-coated helical carbon nanowire end-fired with a dipolar aperture nanoantenna. Our nonresonant helical nanoantenna enables tunable polarization control by swirling surface plasmons on the subwavelength scale and taking advantage of the optical spin-orbit interaction. Four closely packed helical traveling-wave nanoantennas (HTNs) are demonstrated to locally convert an incoming light beam into four beams of tunable polarizations and intensities, with the ability to impart different polarization states to the output beams in a controllable way. Moreover, by near-field coupling four HTNs of opposite handedness, we demonstrate a subwavelength waveplate-like structure providing a degree of freedom in polarization control that is unachievable with ordinary polarization optics and current metamaterials.

| S-EPMC6804798 | biostudies-other

Terahertz magneto-plasmonics using cobalt subwavelength aperture arrays.

Project description:We characterize the terahertz (THz) magneto-plasmonic response of a cobalt-based periodic aperture array. The bare cobalt surface allows for low loss propagation of surface plasmon-polaritons, as evidenced by comparing the reflection from aperture arrays coated with Au and with Co. When an external magnetic field is applied in a polar Kerr geometry, we observe a maximum polarization rotation of ~0.6° and an ellipticity of ~0.35° from the Co-based array. These values are larger than expected based on existing models that include only interband transitions in ferromagnetic metals. We discuss possible reasons for the difference between experiment and theory.

| S-EPMC5607252 | biostudies-literature

Anisotropy modeling of terahertz metamaterials: polarization dependent resonance manipulation by meta-atom cluster.

Project description:Recently metamaterials have inspired worldwide researches due to their exotic properties in transmitting, reflecting, absorbing or refracting specific electromagnetic waves. Most metamaterials are known to have anisotropic properties, but existing anisotropy models are applicable only to a single meta-atom and its properties. Here we propose an anisotropy model for asymmetrical meta-atom clusters and their polarization dependency. The proposed anisotropic meta-atom clusters show a unique resonance property in which their frequencies can be altered for parallel polarization, but fixed to a single resonance frequency for perpendicular polarization. The proposed anisotropic metamaterials are expected to pave the way for novel optical systems.

| S-EPMC4048888 | biostudies-other

Near-field terahertz probes with room-temperature nanodetectors for subwavelength resolution imaging.

Project description:Near-field imaging with terahertz (THz) waves is emerging as a powerful technique for fundamental research in photonics and across physical and life sciences. Spatial resolution beyond the diffraction limit can be achieved by collecting THz waves from an object through a small aperture placed in the near-field. However, light transmission through a sub-wavelength size aperture is fundamentally limited by the wave nature of light. Here, we conceive a novel architecture that exploits inherently strong evanescent THz field arising within the aperture to mitigate the problem of vanishing transmission. The sub-wavelength aperture is originally coupled to asymmetric electrodes, which activate the thermo-electric THz detection mechanism in a transistor channel made of flakes of black-phosphorus or InAs nanowires. The proposed novel THz near-field probes enable room-temperature sub-wavelength resolution coherent imaging with a 3.4 THz quantum cascade laser, paving the way to compact and versatile THz imaging systems and promising to bridge the gap in spatial resolution from the nanoscale to the diffraction limit.

| S-EPMC5347152 | biostudies-literature

A high-efficiency regime for gas-phase terahertz lasers.

Project description:We present both an innovative theoretical model and an experimental validation of a molecular gas optically pumped far-infrared (OPFIR) laser at 0.25 THz that exhibits 10× greater efficiency (39% of the Manley-Rowe limit) and 1,000× smaller volume than comparable commercial lasers. Unlike previous OPFIR-laser models involving only a few energy levels that failed even qualitatively to match experiments at high pressures, our ab initio theory matches experiments quantitatively, within experimental uncertainties with no free parameters, by accurately capturing the interplay of millions of degrees of freedom in the laser. We show that previous OPFIR lasers were inefficient simply by being too large and that high powers favor high pressures and small cavities. We believe that these results will revive interest in OPFIR laser as a powerful and compact source of terahertz radiation.

| S-EPMC6042148 | biostudies-literature

Deterministic Terahertz Wave Control in Scattering Media

Project description:Scattering-assisted synthesis of broadband optical pulses

| S-EPMC9389618 | biostudies-literature

Towards a tunable graphene-based Landau level laser in the terahertz regime.

Project description:Terahertz (THz) technology has attracted enormous interest with conceivable applications ranging from basic science to advanced technology. One of the main challenges remains the realization of a well controlled and easily tunable THz source. Here, we predict the occurrence of a long-lived population inversion in Landau-quantized graphene (i.e. graphene in an external magnetic field) suggesting the design of tunable THz Landau level lasers. The unconventional non-equidistant quantization in graphene offers optimal conditions to overcome the counteracting Coulomb- and phonon-assisted scattering channels. In addition to the tunability of the laser frequency, we show that also the polarization of the emitted light can be controlled. Based on our microscopic insights into the underlying many-particle mechanisms, we propose two different experimentally realizable schemes to design tunable graphene-based THz Landau level lasers.

| S-EPMC4518241 | biostudies-literature

Ultrabright continuously tunable terahertz-wave generation at room temperature.

Project description:The hottest frequency region in terms of research currently lies in the 'frequency gap' region between microwaves and infrared: terahertz waves. Although new methods for generating terahertz radiation have been developed, most sources cannot generate high-brightness terahertz beams. Here we demonstrate the generation of ultrabright terahertz waves (brightness ~0.2?GW/sr·cm(2), brightness temperature of ~10(18)?K, peak power of >50?kW) using parametric wavelength conversion in a nonlinear crystal; this is brighter than many specialized sources such as far-infrared free-electron lasers (~10(16)?K, ~2?kW). We revealed novel parametric wavelength conversion using stimulated Raman scattering in LiNbO3 without stimulated Brillouin scattering using recently-developed microchip laser. Furthermore, nonlinear up-conversion techniques allow the intense terahertz waves to be visualized and their frequency determined. These results are very promising for extending applied research into the terahertz region, and we expect that this source will open up new research fields such as nonlinear optics in the terahertz region.

| S-EPMC4046149 | biostudies-literature

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

Tweets

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data