- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Photonic Spin-Multiplexing Metasurface for Switchable Spiral Phase Contrast Imaging
摘要： As the two most representative operation modes in an imaging system, bright-field imaging and phase contrast optical imaging can extract different morphological information on an object. Developing a miniature and low-cost system capable of switching between these two imaging modes is thus very attractive for a number of applications, such as biomedical imaging. Here, we propose and demonstrate that a Fourier transform setup incorporating an all-dielectric metasurface can perform a two-dimensional spatial differentiation operation and thus achieve isotropic edge detection. In addition, the metasurface can provide two spin-dependent, uncorrelated phase profiles across the entire visible spectrum. Therefore, based on the spin-state of incident light, the system can be used for either diffraction-limited bright-field imaging or isotropic edge-enhanced phase contrast imaging. Combined with the advantages of planar architecture and ultrathin thickness of the metasurface, we envision this approach may open new vistas in the very interdisciplinary field of imaging and microscopy.
关键词： phase contrast imaging,edge detection,orbital angular momentum,Metasurface
更新于2025-09-19 17:13:59
-
[IEEE 2019 Photonics & Electromagnetics Research Symposium - Fall (PIERS - Fall) - Xiamen, China (2019.12.17-2019.12.20)] 2019 Photonics & Electromagnetics Research Symposium - Fall (PIERS - Fall) - A Novel Coding Phase Gradient Metasurface for Wideband RCS Reduction
摘要： In this letter, a new design of metasurface based on coding phase gradient metasurface for wideband radar cross section (RCS) reduction is proposed. The unit cell of the metasurface is composed of a Jerusalem structure and a central circular ring. In order to reduce the burden of the computation time and to optimize design procedure, we use the genetic algorithm and nonlinear fitting method to determine the unit cell geometer. By changing and selecting the parameter of each unit, it is found that the reflection phase of the unit can achieve a stable distribution of phase gradient of the cell among the frequency range of 7.5–26 GHz. In our design, both the random coding sequences and gradient phases in the coding elements are combined to manipulate the EM waves. Four kinds of super-cells with different gradient directions are obtained according to the generalized Snell’s Law, serving as the coding element. A coding metasurface composed of 6 × 6 supercells with random arrangement is designed to improve its RCS reduction. By coding four types of linear-phase gradients in a random pattern, reflected wave can be uniformly diffused. Moreover, the manipulation of waves will be more flexible compared with other designs. The simulated results show that a 10 dB RCS reduction is realized over broadband ranging from 7.5 to 26 GHz.
关键词： nonlinear fitting,coding phase gradient,metasurface,genetic algorithm,RCS reduction
更新于2025-09-19 17:13:59
-
Realization of near-infrared active Fano-resonant asymmetric metasurface by precisely controlling the phase transition of Ge2Sb2Te5
摘要： Realization of near-infrared active Fano-resonant asymmetric metasurface by precisely controlling the phase transition of Ge2Sb2Te5
关键词： Ge2Sb2Te5,metasurface,phase transition,near-infrared,Fano resonance
更新于2025-09-19 17:13:59
-
Polarization-Controlled Plasmonic Structured Illumination
摘要： Structured light in the subwavelength scale is important for a broad range of applications ranging from lithography to imaging. Of particular importance is the ability to dynamically shift the pattern of the fields, which has led to the development of structured illumination microscopy. Further extension of structured illumination to plasmonic systems has enabled imaging beyond diffraction limit. However, structured illumination usually requires complicated optical setups entailing moving mechanical parts. Here a polarization tunable structured plasmonic fields (SPF) is proposed and experimentally demonstrated. The SPF is formed by surface plasmon interference (SPI) generated by a fishbone-shaped metasurface on a thin gold film. Importantly, the SPF can be continuously shifted by merely varying the linear polarization state of an incident beam. The precise control of the fringes of structured illumination and elimination of mechanical control will have great potential in subdiffractional imaging for practical applications.
关键词： Plasmonic,metasurface,structured illumination,subdiffractional imaging
更新于2025-09-19 17:13:59
-
High-Gain Metasurface in Polyimide On-Chip Antenna Based on CRLH-TL for Sub-Terahertz Integrated Circuits
摘要： this paper presents a novel on-chip antenna using standard cMoS-technology based on metasurface implemented on two-layers polyimide substrates with a thickness of 500 μm. the aluminium ground-plane with thickness of 3 μm is sandwiched between the two-layers. concentric dielectric-rings are etched in the ground-plane under the radiation patches implemented on the top-layer. the radiation patches comprise concentric metal-rings that are arranged in a 3 × 3 matrix. The antennas are excited by coupling electromagnetic energy through the gaps of the concentric dielectric-rings in the ground-plane using a microstrip feedline created on the bottom polyimide-layer. the open-ended feedline is split in three-branches that are aligned under the radiation elements to couple the maximum energy. in this structure, the concentric metal-rings essentially act as series left-handed capacitances CL that extend the effective aperture area of the antenna without affecting its dimensions, and the concentric dielectric rings etched in the ground-plane act as shunt left-handed inductors LL, which suppress the surface-waves and reduce the substrates losses that leads to improved bandwidth and radiation properties. The overall structure behaves like a metasurface that is shown to exhibit a very large bandwidth of 0.350–0.385 THz with an average radiation gain and efficiency of 8.15dBi and 65.71%, respectively. It has dimensions of 6 × 6 × 1 mm3 that makes it suitable for on-chip implementation.
关键词： metasurface,integrated circuits,on-chip antenna,polyimide substrate,sub-terahertz
更新于2025-09-19 17:13:59
-
Metasurface-enabled interference mitigation in visible light communication architectures
摘要： Light can be used for wireless information transmission apart from illumination; that is the key idea behind visible-light communication (VLC), one of the disruptive technologies of our days. It combines remarkably high data rates due to ultrashort wavelengths with huge reliability and security due to small distances; nevertheless, it substantially suffers from interference of neighboring light sources in multiple-link configurations. In this manuscript, we investigate a pair of light emitting diodes interfering each other and propose a simple nanoslit metasurface that radically increases the directivity of the transmitting beams. As a result, enhancement of the signal-to-interference ratio by several orders of magnitude is reported. The considered generic setup retains its beneficial features in the presence of realistic design defects and, accordingly, may inspire standardization efforts towards the adoption of VLC in next-generation heterogeneous communication networks.
关键词： directivity,metasurface,visible-light communications,radiation pattern,indoor environment
更新于2025-09-19 17:13:59
-
Boosting ultrathin aSi-H solar cells absorption through a nanoparticle cross-packed metasurface
摘要： Hydrogenated amorphous silicon (a-Si:H) solar cells have some performance limitations related to the mobility and lifetime of their carriers. For this reason, it is interesting to explore thin-film solutions, achieving a tradeoff between photons optical absorption and the electrical path of the carriers to get the optimum thickness. In this work, we propose the insertion of a metasurface based on a cross-patterned ITO contact film, where the crosses are filled with nanospheres. We numerically demonstrate that this configuration improves the photogenerated current up to a 40% by means of the resonant effects produced by the metasurface, being independent on the impinging light polarization. Light handling mechanisms guide light into the active and auxiliary layers, increasing the effective absorption and mitigating the Staebler-Wronski effect. The selection of optimum materials and parameters results in nanospheres of ZnO with a 220 nm radius.
关键词： a-Si hydrogenated solar cell,Short-circuit current,Metasurface,Absorption enhancement,Nanostructure
更新于2025-09-19 17:13:59
-
Liquid crystal programmable metasurface for terahertz beam steering
摘要： The coding metasurface integrated with tunable materials offers an attractive alternative to manipulate the THz beam dynamically. In this work, we demonstrate a THz programmable metasurface based on liquid crystal. The phase pro?le on the metasurface could be dynamically manipulated by switching the “0” and “1” states of each element. The programmable metasurface could de?ect the THz beam using the designed coding sequence, and a maximum de?ection angle of 32(cid:2) has been achieved. The presented design opens a route of beamforming for THz communication.
关键词： beamforming,programmable metasurface,THz beam steering,liquid crystal
更新于2025-09-19 17:13:59
-
[IEEE 2019 TEQIP III Sponsored International Conference on Microwave Integrated Circuits, Photonics and Wireless Networks (IMICPW) - Tiruchirappalli, India (2019.5.22-2019.5.24)] 2019 TEQIP III Sponsored International Conference on Microwave Integrated Circuits, Photonics and Wireless Networks (IMICPW) - Metasurface Loaded Patch Antenna For Wi-Fi Applications
摘要： Design of rectangular patch antenna with hexagonal shaped metasurfaces for Wi-Fi applications. In this paper, the corners of the rectangular patch are replaced by means of circular structures. This will remove the sharp transition and the desired frequency is achieved with smaller dimension in comparison with normal rectangular patch. A layer of metasurface elements is added with the antenna to improve the return loss. The proposed antenna is radiating at resonant frequency of 2.4 GHz with the gain value of 6.8 dB. The bandwidth is achieved from 2.37 GHz to 2.43 GHz around the resonant frequency of 2.4 GHz.
关键词： metasurface,antenna gain,radiation pattern,Wi-Fi
更新于2025-09-16 10:30:52
-
[IEEE 2019 International Conference on Optical MEMS and Nanophotonics (OMN) - Daejeon, Korea (South) (2019.7.28-2019.8.1)] 2019 International Conference on Optical MEMS and Nanophotonics (OMN) - Metasurfaces for Display and Imaging Applications
摘要： Metasurfaces composed of subwavelength nanostructures have shown unprecedented abilities to control electromagnetic waves, and have been expected to be applied for the next generation imaging devices. In this keynote talk, general introduction of optical metasurfaces will be introduced with their physical instruments and applications. Then, we will discuss recent advances on metasurface applications for holography and augmented reality. In particular, full complex-amplitude modulated holograms and ultra-wide augmented reality imaging will be mainly discussed with our theoretical and experimental demonstrations. Our perspectives for the future of this area will also be discussed.
关键词： Metasurface,Augmented Reality,Optical display,Holography
更新于2025-09-16 10:30:52