Reconfigurable Circularly Polarized Hemispherical DRA Using Plasmonic Graphene Strips for MIMO Communications

Plasmonics - This paper investigates the radiation characteristics of a Hemispherical- Dielectric Resonator Antenna (DRA) loaded with graphene strips and fed by ridge-gap waveguide (RGW)...     

Reconfigurable Multi-beam On-Chip Patch Antenna Using Plasmonics Parasitic Graphene Strip Array

Plasmonics - This paper introduces on-chip patch antenna with electronic beam switching using graphene strip array for wireless communications at 415 GHz. The on-chip patch antenna is...     

Multi-Band Plasmonic Platform Utilizing UT-Shaped Graphene Antenna Arrays

Plasmonics - In this work, we introduce a plasmonic platform based on UT-shaped graphene antenna arrays. The proposed multi-resonant platform shows three different resonances, which can be...     

A Polarization-Independent SPR Fiber Sensor

The resonance of surface plasma waves in metallic layers is a strongly polarization-dependent phenomenon by the very nature of the physical effect responsible of that resonance. This implies the necessity of polarization-controlling elements to be added to any operative surface-plasmon-resonance-based sensor. A fully symmetrical, circular-section double deposition of a metallic and a dielectric layer on a uniform-waist tapered optical fiber (SymDL-UWT) permits us to completely eliminate the dependence on polarization of the plasmon excitation, with the corresponding operative advantages and basic theoretical consequences. We depict the fabrication process of these transducers, which is based on the use of a simple and efficient rotating element developed by us, and show the characteristics of the produced devices. No such device has been depicted up to date. As our experimental results show, this kind of devices can be considered a very good option for the development of simple, compact, and efficient chemical and biological sensors.     

Reconfigurable Plasmonic Logic Gates

Reconfigurable one-, two-, and three-bit plasmonic logic gate configurations have been proposed, which work by covering a straight slot waveguide with materials with tunable dielectric constants, such as graphene. By encoding the logic states in the values of dielectric constants as opposed to different waveguides, the plasmon excitation problems are minimized and the simplified logic gate configurations could be easily implemented.

     

Visible-light Induced Reduction of Graphene Oxide Using Plasmonic Nanoparticle

Present work demonstrates the simple, chemical free, fast, and energy efficient method to produce reduced graphene oxide (r-GO) solution at RT using visible light irradiation with plasmonic nanoparticles. The plasmonic nanoparticle is used to improve the reduction efficiency of GO. It only takes 30 min at RT by illuminating the solutions with Xe-lamp, the r-GO solutions can be obtained by completely removing gold nanoparticles through simple centrifugation step. The spherical gold nanoparticles (AuNPs) as compared to the other nanostructures is the most suitable plasmonic nanostructure for r-GO preparation. The reduced graphene oxide prepared using visible light and AuNPs was equally qualitative as chemically reduced graphene oxide, which was supported by various analytical techniques such as UV-Vis spectroscopy, Raman spectroscopy, powder XRD and XPS. The reduced graphene oxide prepared with visible light shows excellent quenching properties over the fluorescent molecules modified on ssDNA and excellent fluorescence recovery for target DNA detection. The r-GO prepared by recycled AuNPs is found to be of same quality with that of chemically reduced r-GO. The use of visible light with plasmonic nanoparticle demonstrates the good alternative method for r-GO synthesis.     

Optimizing the Sensing Efficiency of Plasmonic Based Gas Sensor

Plasmonics - This paper investigates the behavior of the surface plasmon polaritons (SPPs) on dielectric-metal interface using Ag thin film on glass substrate. The Kretschman configuration, which...     

Distributed MEMS Sensors Using Plasmonic Antenna Array Embedded Sagnac Interferometer

A micro Sagnac interferometer is proposed for electron cloud distributed sensors formed by an integrated (micro-electro-mechanical systems) MEMS resonator structure. The Sagnac interferometer consists of four microring probes integrated into a Sagnac loop. Each of the microring probes is embedded with the silver bars to form the plasmonic wave oscillation. The polarized light of 1.50 µm wavelength is input into the interferometer, which is polarized randomly into upstream and downstream directions. The polarization outputs can be controlled by the space–time input at the Sagnac port. Electrons are trapped and oscillated by the whispering gallery modes (WGMs), where the plasmonic antennas are established and applied for wireless fidelity (WiFi) and light fidelity (LiFi) sensing probes, respectively. Four antenna gains are 2.59 dB, 0.93 dB, 1.75 dB, and 1.16 dB, respectively. In manipulation, the sensing probe electron densities are changed by input source power variation. When the electron cloud is excited by the microscopic medium, the change in electron density is obtained and reflected to the required parameters. Such a system is a novel device that can be applied for brain-device interfering with the dual-mode sensing probes. The obtained WGM sensors are 1.35 µm^?2, 0.90 µm^?2, 0.97 µm^?2, and 0.81 µm^?2, respectively. The WGMs behave as a four-point probe for the electron cloud distributed sensors, where the electron cloud sensitivities of 2.31 prads^?1mm³ (electrons)^?1, 2.27 prads^?1mm³ (electrons)^?1, 2.22 prads^?1mm³(electrons)^?1, and 2.38 prads^?1mm³(electrons)^?1 are obtained, respectively.

     

Electronic Beam-Scanning Strip-Coded Graphene Leaky-Wave Antenna Using Single Structure

Plasmonics - In this paper, a reconfigurable graphene leaky-wave antenna (GLWA) with electronic beam scanning capability for THz communications system is proposed. It consists of graphene strips...     

Plasmonic Sensor Using a Combination of Grating and Prism Couplings

Plasmonics - Surface plasmon-polariton (SPP) waves guided by an interface of a metal and a dielectric material with a combination of grating- and prism-coupled configurations are theoretically...     

Tunable Plasmonic Nanolaser Based on Graphene

Plasmonics - Surface plasmon polariton nanolaser, which can achieve all-optical circuits and optoelectronic integration, is a major research area in nano-optics. We propose a novel tunable...     

Multilayer Hybrid Plasmonic Nano Patch Antenna

This is the first report of a hybrid plasmonic nano patch antenna having metal insulator metal (HMIM) multilayer configuration. It is designed in a footprint area of 1.7 × 1.175 μm² to resonate at 1.55 μm wavelength. The proposed antenna is inset fed by an HMIM plasmonic waveguide for achieving proper impedance matching. It is observed, through electromagnetic numerical simulation, that the proposed plasmonic nano patch antenna emits a directional beam with a bandwidth, gain, and efficiency of 0.194 μm, 8.3 dB, and 96% respectively, which are significantly higher than previously reported designs. Since inset-fed antennas are suitable for developing high-gain antenna array, hence further, we examined antenna performance by designing antenna array. The proposed antenna is practically realizable and can be fabricated using standard semiconductor fabrication process. Moreover, it could be used for numerous chip scale applications such as wireless interconnects energy harvesting, photoemission, photo detection, scattering, heat transfer, spectroscopy, and optical sensing.

     

Nonlocal Plasmonic Modes and Plasmonic Band Structures in Cylindrically Curved Graphene

Plasmonics - In this paper, hydrodynamic model has been analytically solved to investigate the nonlocal plasmons in cylindrically curved graphene layers. Within the quasi-static approximation, the...     

Large Circular Dichroism in MDM Plasmonic Metasurface with Subwavelength Crescent Aperture

A metal–dielectric–metal planar chiral plasmonic metasurface is proposed and its circular dichroism (CD) property is numerically studied using finite difference time domain computation. The unit cell of planar plasmonic metasurface consists of crescent apertures that are arranged in a particular orientation. The proposed structure exhibits multiband circular dichroism at near-infrared wavelengths. By changing the orientational symmetry, the structure shows a drastic reduction in the circular dichroism. Passive controlling of orientational symmetry shows a systematic change in the sign of the CD. High incident angular tolerance of the planar chiral plasmonic metasurface (PCPM) to about 15° suggests the proposed structure might be useful for CD spectroscopy.

     

Ultra-broadband Polarization-Independent Wide-Angle THz Absorber Based on Plasmonic Resonances in Semiconductor Square Nut-Shaped Metamaterials

Plasmonics - Metamaterials are considered to be a promising candidate of making THz absorber for function devices to replace natural materials. Based on geometry evolution, the electromagnetic...     

A Hybrid Plasmonic Modulator Based on Graphene on Channel Plasmonic Polariton Waveguide

A hybrid plasmonic modulator based on graphene on channel plasmonic polariton waveguide was proposed to overcome the difficulty in achieving high-speed modulation on the nanometric plasmonic waveguide platform. The extinction ratio and the figure of merit of the proposed modulator were analyzed in detail, and a tradeoff between them was found due to the intrinsic loss of the channel plasmonic polariton waveguide. And an optimized hybrid plasmonic modulator with large modulation bandwidth of 0.662 THz, low power consumption of 118.7 fJ/bit, and short device length of 7.680 μm was obtained theoretically. In addition, the proposed hybrid plasmonic modulator based on graphene on channel plasmonic polariton waveguide is easy to fabricate and provides a potential solution for the high-speed plasmonic modulator.

     

Magnetically Controlled Nanofocusing of a Graphene Plasmonic Lens

In this paper, we propose a method to tailor the nanofocusing of plasmons on graphene plasmonic lens, which is composed of graphene and circular dielectric gratings of magneto-optical material beneath it. With an external magnetic field parallel to graphene surface, the magneto-optical effect of substrate leads to the difference in modal indices of graphene plasmons, which also introduces an additional relative phase difference between these two plasmons during excitation and propagation. Together, these two effects enable us to tailor the position of focal points through external magnetic field, which has been described by an analytical approach based on phase matching and verified by numerical simulations. With an operation wavelength of 8500 nm and an external magnetic field from B = ?1 T to B = 1 T, a shift distance over one and a half times of plasmons wavelength for focal points or donut-shaped field profiles can be obtained under linearly or circularly polarized light. The proposed scheme has potentials in diverse applications, such as the tunable nanofocusing and particle manipulation.     

Graphene Doping Induced Tunability of Nanoparticles Plasmonic Resonances

Interest in graphene has been widely increasing since its discovery in 2004. Research on graphene for plasmonic applications has also boomed due to the high potential of these systems. In this article, we discuss the possible interaction between metallic NPs and graphene monolayer. We show how the contact between metallic NPs and graphene results in graphene doping. More importantly, we experimentally put into evidence the possible modulation of the plasmonic resonance of NPs by graphene doping. Understanding and evidencing this interaction is highly important both from a fundamental point of view and for specific applications such as active plasmonic devices.

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