Results 61 to 70 of about 6,073 (241)

Metamaterial Antennas Enhance MRI of the Eye and Occipital Brain

Advanced Materials, EarlyView.
A radiofrequency antenna platform comprising planar and bend configurations is developed, incorporating structurally integrated epsilon‐negative metamaterial unit cells to enhance MRI. These antennas enable high‐resolution in vivo human MRI of the eye, orbit, and occipital brain. Comprehensive validation, including simulations, phantom experiments, SAR,
Nandita Saha, Bilguun Nurzed, Mostafa Berangi, Andre Kuehne, Helmar Waiczies, Igor Fabian Tellez Ceja, Xiang Hu, Thomas Gladytz, Lisa Krenz, Dave Huebler, Beate Endemann, Claudia Brockmann, Ebba Beller, Oliver Stachs, Thoralf Niendorf   +14 more
wiley   +1 more source

Infrared Absorption Efficiency Enhancement of the CMOS Compatible Thermopile by the Special Subwavelength Hole Arrays

Applied Sciences, 2020
The infrared absorption efficiency (IAE) enhancement of the complementary-metal-oxide-semiconductorCMOS compatible thermopile with special subwavelength hole arrays in an active area was numerically investigated by the finite-difference time-domain ...
Yun-Ying Yeh, Chih-Hsiung Shen, Chi-Feng Chen   +2 more
doaj   +1 more source

Transducers Across Scales and Frequencies: A System‐Level Framework for Multiphysics Integration and Co‐Design

Advanced Materials Technologies, EarlyView.
Transducers convert physical signals into electrical and optical representations, yet each mechanism is bounded by intrinsic trade‐offs across bandwidth, sensitivity, speed, and energy. This review maps transduction mechanisms across physical scale and frequency, showing how heterogeneous integration and multiphysics co‐design transform isolated ...
Aolei Xu, Mengyao Xiao, Zhouli Sui, Yinpeng Wang, Daoye Zheng, Yuxin Liu, Luwei Wang, Huajun Liu, Chengkuo Lee   +8 more
wiley   +1 more source

Anomalous wavefront manipulation and broadband sound absorption by metasurfaces with periodic subwavelength modulation

AIP Advances, 2018
Both periodic subwavelength structures and phase gradient metasurfaces have opened up new degrees of freedom to manipulate the acoustic waves respectively.
Li Cai, Jihong Wen, Dianlong Yu, Zhimiao Lu, Xing Chen, Xiang Zhao   +5 more
doaj   +1 more source

Terahertz Chiral Metamaterials Enabling Broadband Polarization Conversion Using Polarization Guiding Effect

Advanced Materials Technologies, EarlyView.
A broadband terahertz polarization rotator consisting of twistingly stacked silicon–air metagratings is designed based on the polarization guiding effect and experimentally shown to achieve 90° linear polarization rotation for both TE and TM incidences.
Yun‐Seok Choi, Tae Gwan Park, Antoinette J. Taylor, Hou‐Tong Chen, Abul K. Azad   +4 more
wiley   +1 more source

Responsive Visible‐Wavelength Metasurfaces from Porous Silicon Based on Fano Guided‐Mode Resonance

Advanced Optical Materials, EarlyView.
The article introduces mesoporous silicon metasurfaces (pSi‐MS) supporting Fano guided‐mode resonances in the visible regime. By combining top‐down lithographic patterning of 2D gratings with bottom‐up electrochemical porosification, the approach realizes a new class of responsive metasurfaces, enabling highly sensitive and portable platforms for small
Tomoshree Dash, Saddam Gafsi, Estevao Marques Dos Santos, Ivan Kravchenko, Judson D. Ryckman   +4 more
wiley   +1 more source

Dynamically Electrically Tunable Broadband Absorber Based on Graphene Analog of Electromagnetically Induced Transparency

IEEE Photonics Journal, 2016
A broadband absorber, which is composed of graphene analog of electromagnetically induced transparency (EIT) and a metal ground plane spaced by a thin SiO 2 dielectric layer, is proposed and investigated.
Gang Yao, Furi Ling, Jin Yue, Chunya Luo, Qin Luo, Jianquan Yao   +5 more
doaj   +1 more source

Field Structures and Singularities in Subwavelength Optics

Vestnik Moskovskogo Universiteta, Seriya 3: Fizika, Astronomiya
A brief overview of the current state of the problem of electromagnetic field singularities arising from the refraction and scattering of light by material objects is given. The discussion begins with caustics arising from ray tracing in geometric optics and consistently moves toward increasing the accuracy of consideration and decreasing the scale ...
Tribelsky, M. I., Luk'yanchuk, B. S.
openaire   +2 more sources

Subwavelength-Grating Metamaterial Structures for Silicon Photonic Devices [PDF]

Proceedings of the IEEE, 2018
Segmenting silicon waveguides at the subwave-length scale produce an equivalent homogenous material. The geometry of the waveguide segments provides precise control over modal confinement, effective index, dispersion and birefringence, thereby opening up new approaches to design devices with unprecedented performance.
Robert Halir, Alejandro Ortega-Monux, Daniel Benedikovic, Goran Z. Mashanovich, J. Gonzalo Wanguemert-Perez, Jens H. Schmid, Inigo Molina-Fernandez, Pavel Cheben   +7 more
openaire   +5 more sources

Controlling Ultrafast Photonic‐Plasmonic Coupling in a Hybrid Platform for Biosensing Applications

Advanced Optical Materials, EarlyView.
A metal–dielectric hybrid composed of gold nanocaps on opal exhibits a broad near‐infrared plasmonic resonance interacting with the photonic bandgap under ultrafast transient conditions. This coupling can be controlled by varying the excitation wavelength and is responsive to bacterial deposition, opening new opportunities for ultrafast biosensing ...
Diego Florio, Andrea Chiappini, Laura Pasquardini, Mario Barozzi, Monica Bollani, Salvatore Stagira, Tersilla Virgili   +6 more
wiley   +1 more source