Search results for "plasmoni"
showing 10 items of 135 documents
Synergistic enhancement via plasmonic nanoplate-bacteria-nanorod supercrystals for highly efficient SERS sensing of food-borne bacteria
2017
Bio-sensing techniques utilizing metallic nanoparticles as a probe have gained more and more attention and play today an important role in the detection of bacteria. To date, although several sensing materials have been tested, there is still a long way to go to achieve a fast, low-cost, ultrasensitive and multifunctional substrate suitable for a universal biosensor for detection of bacterial cells. Here, we report a novel probe design based on anisotropic plasmonic nanoparticles organized to a biocompatible 3D bio-inorganic scaffold, i.e., nanoplate-bacteria-nanorod supercrystals (NBNS) with extremely high surface-enhanced Raman spectroscopic (SERS) activity as a model of synergistic plasm…
Dielectric and plasmonic waveguides based on quantum dots embedded in polymers
2013
espanolEn este trabajo se propone una revision de la implementacion de guias de onda activas basadas en la dispersion de puntos cuanticos coloidales (QDs) en polimeros. Para ello, guias de onda planas fueron fabricadas embebiendo distintos tipos de nanoestructuras semiconductoras con emision en el visible e infrarrojo (CdS, CdTe, CdSe, PbS) en PMMA, encontrandose las condiciones optimas para el guiado de su fotoluminiscencia y sus propiedades de ganancia y atenuacion. Si varios tipos de puntos son dispersados en la misma capa se propagan varios colores, siendo posible obtener luz blanca con las proporciones adecuadas de rojo, verde y azul. Asimismo, el guiado puede ser mejorado si una cubie…
Applications of DNA self-assembled structures in nanoelectronics and plasmonics
2018
In this thesis, the potential applications of DNA self-assembled structures were explored in both nanoelectronics and plasmonics. The works can be divided into two parts: electrical characterization of unmodified multilayered DNA origami and DNA-gold-nanoparticle conjugates after they were trapped between gold nanoelectrodes by dielectrophoresis, and the development of a novel fabrication method using DNA origami as a template for smooth, high resolution metallic nanostructures as well as optical characterization of them. One of the biggest challenges in self-assembled nanoelectronic devices is to connect them to macroscopic circuits. Dielectrophoretic (DEP) trapping has been used extensivel…
Trade-off Performance of Optical Nanoantennas for Solar Energy Harvesting Applications
2019
In this paper, the optimum behaviour of optical nanoantennas, in terms of impedance, directivity, available power, and field enhancement, at a resonance frequency of about 350 THz, will be shown. Optimum configurations are obtained by varying nanoantennas geometry in order to maximize the available power, enhancing the electric field in gap proximity and so the absorptivity. Moreover, the simulation results for aluminum nanoantennas on a three-layers substrate, will be reported, and a trade-off performance comparison among different antennas will be discussed. This study can guide both the engineering and the fabrication of plasmonic nanoantennas.
A High-Efficiency Optical Energy Harvester based on a Low-Impedance Plasmonic Nanoantenna
2022
In this paper, for the first time, an investigation in terms of efficiency of an energy harvester based on a plasmonic nanorectenna array is proposed. The novel proposed mirrored-arrowhead nanoantenna presents a very low impedance value at the resonant frequency which reduces the mismatching between the antenna and rectifier circuit. Simulation results carried out by the CST 2020 Studio show a resistance value equal to 1.1 kohms at about 350 THz and a very wide bandwidth as the equivalent RF rhombic antenna. This study paves the way to nanoantennas for high-efficiency electromagnetic energy harvesting applications overcoming the photovoltaic technology.
Hybrid materials based on conductive polymers for energy harvesting
2022
Uno de los objetivos de la Organización de las Naciones Unidas (ONU) para el Desarrollo Sostenible 2030 es obtener energía asequible y no contaminante. Por este motivo, se recomiendan encarecidamente las mejoras en la eficiencia energética y las fuentes de energía verde como soluciones óptimas para reducir las emisiones de dióxido de carbono y, por tanto, reducir la huella de carbono de nuestra sociedad. Las emisiones de carbono se han cuadriplicado desde 1950 y actualmente contribuyen en torno al 80 % de las emisiones de gases de efecto invernadero. Como resultado de este cambio, el clima global sufre cambios en las tendencias globales de lluvia y una reducción en los casquetes polares. Co…
Reversible Strong Coupling in Silver Nanoparticle Arrays Using Photochromic Molecules
2012
International audience; In this Letter, we demonstrate a reversible strong coupling regime between a dipolar surface plasmon resonance and a molecular excited state. This reversible state is experimentally observed on silver nanoparticle arrays embedded in a polymer film containing photochromic molecules. Extinction measurements reveal a clear Rabi splitting of 294 meV, corresponding to ∼13% of the molecular transition energy. We derived an analytical model to confirm our observations, and we emphasize the importance of spectrally matching the polymer absorption with the plasmonic resonance to observe coupled states. Finally, the reversibility of this coupling is illustrated by cycling the …
Asymmetrical waveguide coupling by a tilted metal nanocone
2017
Kasvava uusiutuvan energian tarve ajaa tiedeyhteisöä etsimään uusia vihreitä energian lähteitä. Osana tätä tavoitetta, WISC-projekti pyrkii yhdistämään infrapunaa keräävän aurinkopaneelin normaaliin ikkunaan. Tässä tutkimuksessa me tutkimme sisääntulevan valon kytkeytymistä kallistuneesta kultananokartiosta laattamaisen aaltojohteen ohjattuihin aaltojohdemoodeihin; tavoitteena on esittää epäsymmetristä aaltojohteeseen kytkeytymistä. Tutkimus suoritettiin simuloimalla Comsolissa käyttäen kolmiulotteista äärellisten elementtien menetelmää. Ulospäin suuntautuva aaltojohteeseen sironneen valon energiavuo mitattiin 2.1 aallonpituuden päässä nanokartiosta. Tulokset viittaavat kahden samanaikaisen…
Plasmonic Stripes in Aqueous Environment Co-Integrated With Si3N4 Photonics
2018
We demonstrate the design, fabrication, and the experimental characterization of gold-based plasmonic stripes butt-coupled with low-pressure-chemical-vapor-deposition (LPCVD)-based Si3N4 waveguides for the excitation of surface-plasmon-polariton (SPP) modes in aqueous environment. Plasmonic gold stripes, in aqueous environment, with cross-sectional dimensions of 100 nm × 7 μm were interfaced with 360 nm × 800 nm Si3N4 waveguides cladded with low-temperature-oxide, exploiting linear photonic tapers with appropriate vertical (VO) and longitudinal (LO) offsets between the plasmonic and photonic waveguide facets. An interface insertion loss of 2.3 ± 0.3 dB and a plas…
Spatial localization of hotspots in Fano-resonant plasmonic oligomers for surface-enhanced coherent anti-Stokes Raman scattering
2020
AbstractRealization of Fano resonance in plasmonic oligomers is often exploited to design efficient plasmonic substrates for surface-enhanced coherent anti-Stokes Raman scattering. Disk-type Fano-resonant plasmonic oligomers are widely used to enhance the Raman signal of the probe material. Generally, hot spots are generated in those oligomers at different spatial locations at different wavelengths and only a few spatially overlapping hot spots at multiple wavelengths can be achieved with oblique incidence of excitation light. In this work, we proposed hexagonal gold nanoparticle based Fano-resonant plasmonic oligomers that can yield higher number of spatially overlapped hot spots compared …