A5091107166- Plasmonic and Surface Plasmon Research
- Gold and Silver Nanoparticles Synthesis and Applications
- Photonic Crystals and Applications
- Photonic and Optical Devices
- Metamaterials and Metasurfaces Applications
- Near-Field Optical Microscopy
- Optical Coatings and Gratings
- Force Microscopy Techniques and Applications
- Integrated Circuits and Semiconductor Failure Analysis
- Advanced Fluorescence Microscopy Techniques
- Orbital Angular Momentum in Optics
- Gas Sensing Nanomaterials and Sensors
- Nonlinear Optical Materials Studies
- Polydiacetylene-based materials and applications
- Anodic Oxide Films and Nanostructures
- Thermal Radiation and Cooling Technologies
- Advanced Antenna and Metasurface Technologies
- Copper-based nanomaterials and applications
- Nanowire Synthesis and Applications
- Advanced Photocatalysis Techniques
- Advanced biosensing and bioanalysis techniques
- Advanced Memory and Neural Computing
- Optical and Acousto-Optic Technologies
- Photoreceptor and optogenetics research
- Semiconductor materials and devices
King's College London
2013-2024
London Centre for Nanotechnology
2018-2024
Instituto de Óptica "Daza de Valdés"
2015
King's College Hospital
2013
Queen's University Belfast
2003-2010
Dynamic Graphics (United States)
1994
Controlling coherent electromagnetic interactions in molecular systems is a problem of both fundamental interest and important applicative potential the development photonic opto-electronic devices. The strength these determines absorption emission properties molecules coupled to nanostructures, effectively governing optical such composite metamaterial. Here we report on observation strong coupling between plasmon supported by an assembly oriented gold nanorods (ANR) exciton. We show that...
Lattice modes have been proposed as a means to engineer and control the linewidth spectral position of optical resonances in arrays metallic nanoparticles sustaining localized surface plasmon (LSP) resonances.Lattice are produced by interference LSP-enhanced in-plane scattered light, leading Fano-like lineshape with reduced linewidth.In this paper, we study lattice supported gold aluminium nanoparticle visible UV, both experimentally theoretically.The measured simulated dispersion curves...
Here we present a roadmap on Photonic metasurfaces. This document consists of number perspective articles different applications, challenge areas or technologies underlying photonic Each will introduce the topic, state art as well give an insight into future direction subfield.
The enhanced optical properties of metal films periodically perforated with an array sub-wavelength size holes have recently been widely studied in the field surface plasmon optics. ability to design transmission such nanostructures, which act as plasmonic crystals, by varying their geometrical parameters gives them great flexibility for numerous applications photonics, opto-electronics, and sensing. Transforming these passive elements into devices that may be actively controlled has...
We experimentally demonstrate a low-loss multilayered metamaterial exhibiting double-negative refractive index in the visible spectral range. To this end, we exploit second-order magnetic resonance of so-called fishnet structure. The nature employed resonance, together with effect interacting adjacent layers, results figure merit as high 3.34. A wide range negative is achieved, covering wavelength region between 620 and 806 nm only two different designs.
Nonlinear optical materials comprise the foundation of modern photonics, offering functionalities ranging from ultrafast lasers to switching, harmonic and soliton generation. Optical nonlinearities are typically strong near electronic resonances a material thus provide limited tuneability for practical use. Here we show that in plasmonic nanorod metamaterials, Kerr-type nonlinearity is not by nonlinear properties constituents. Compared with gold's nonlinearity, measured absorption refraction...
One of the basic functionalities photonic devices is ability to manipulate polarization state light. Polarization components are usually implemented using retardation effect in natural birefringent crystals and, thus, have a bulky design. Here, we demonstrated manipulation light by employing thin subwavelength slab metamaterial with an extremely anisotropic effective permittivity tensor. properties incident on regime hyperbolic, epsilon-near-zero, and conventional elliptic dispersions were...
Hyperbolic metamaterials comprised of an array plasmonic nanorods provide a unique platform for designing optical sensors and integrating nonlinear active nanophotonic functionalities. In this work, the waveguiding properties mode structure planar anisotropic metamaterial waveguides are characterized experimentally theoretically. While ordinary modes typical guided highly waveguides, extraordinary modes, below effective plasma frequency, exist in hyperbolic slab form bulk plasmon-polaritons,...
The requirements for spatial and temporal manipulation of electromagnetic fields on the nanoscale have recently resulted in an ever-increasing use plasmonics achieving various functionalities with superior performance to those available from conventional photonics. For these applications, ohmic losses resulting free-electron scattering metal is one major limitation plasmonic structures. In low-frequency regime, can be reduced at low temperatures. this work, we study effect temperature...
Gold-core/palladium-shell metamaterials for hydrogen detection are presented. The more than 30% change in both the reflection and transmission from metamaterial layer that is observed when exposed to 2% mixture clearly noticeable naked eye as a brightness of light transmitted by metamaterial. This sensor should make contribution safety processes involving hydrogen. efficient accurate extremely important because potential hazards at even very low concentrations atmosphere. We describe novel,...
Plasmonic nanostructures were initially developed for sensing and nanophotonic applications but, recently, have shown great promise in chemistry, optoelectronics, nonlinear optics. While smooth plasmonic films, supporting surface plasmon polaritons, individual nanostructures, featuring localized plasmons, are easy to fabricate use, the assemblies of optical antennas metamaterials provide many additional advantages related engineering mode structure (and thus, resonances given spectral...
A series of thin films comprising gold nanorods embedded in an alumina matrix have been fabricated with lengths ranging from 75 to $330\phantom{\rule{0.3em}{0ex}}\mathrm{nm}$. Their optical properties, expressed terms extinction $\ensuremath{-}\mathrm{ln}(T)$, where $T$ is transmittance, measured as a function wavelength, rod length, angle incidence, and incident polarization state. The results are compared Maxwell-Garnett based theory modified take into account the strongly anisotropic...
Arrays of nickel and gold nanorods have been grown on glass silicon substrates using porous alumina templates less than 500 nm thickness. A method is demonstrated for varying the diameter whilst keeping spacing constant. Optical extinction spectra show two distinct maxima associated with transverse longitudinal axes rods. Adding small quantities oxygen to aluminium before anodization found improve sharpness peaks. The spectral position peak shown be sensitive nanorod constant length spacing....
Amplified spontaneous emission of surface plasmon polaritons (SPPs) at the interface a resonant gain medium has been observed. The amplification is accompanied by significant spectral narrowing and limits available for compensation SPP propagation losses. effect similar to deteriorating influence amplified in laser resonators.
We demonstrate that the coupling between plasmonic modes of oriented metallic nanorods results in formation an extended (guided) mode nanorod array. The electromagnetic field distribution associated to this is found be concentrated within assembly and propagates normally long axes, similar a photonic waveguided by anisotropic slab. This collective determines optical properties assemblies can tuned wide spectral range changing array geometry. geometry represents unique opportunity for light...
We experimentally demonstrate suppressed absorption and stimulated emission of surface plasmon polaritons (SPP) leading to all-plasmonic modulation an SPP signal propagating at the interface between a metal gain medium; these observations are supported by developed theory. The use copropagating control waves can provide more than 10 times efficient compared out-of-plane pumping opens up possibility realize integratable plasmonic components for active nanophotonic circuitry.
Intranasal administration is becoming increasingly more attractive as a fast delivery route to the brain for therapeutics circumventing blood-brain barrier (BBB). Gold nanorods (AuNRs) demonstrate unique optical and biological properties compared other gold nanostructures due their high aspect ratio. In this study, we investigated first time region-specific distribution of AuNRs potential drug platform central nervous system (CNS) therapy following intranasal mice using battery analytical...
The optical properties of metallic nanorod arrays acting as plasmonic nanoantennas have been studied. Large area consisting bare Au nanorods diameter and length tuneable in the range 20--40 $200--400\phantom{\rule{0.3em}{0ex}}\mathrm{nm}$, respectively, spacing about $40--100\phantom{\rule{0.3em}{0ex}}\mathrm{nm}$ electrochemically fabricated using templates anodized nanoporous aluminium oxide. We demonstrate a very strong sensitivity their resonant to both presence dielectric load (which is...
The electro-optic response of a cell consisting thin layer liquid crystal deposited onto gold nanorods embedded in film alumina with transparent top electrode has been investigated. For p-polarized light incident from the side, extinction peak associated nanorod longitudinal plasmon resonance is completely suppressed. could be recovered by applying an external electric field parallel to long axis nanorods. No suppression observed when was side cell. effect explained polarization properties crystal.
Optical sensors for ultrasound detection provide high sensitivity and bandwidth, essential photoacoustic imaging in clinical diagnostics biomedical research. Implementing plasmonic metamaterials a non-resonant regime facilitates sub-nanosecond, highly sensitive detectors while eliminating cumbersome optical alignment necessary resonant sensors. As service to our authors readers, this journal provides supporting information supplied by the authors. Such materials are peer reviewed may be...
The ability to control the rate of spontaneous emission via design nanostructured materials with appropriate electromagnetic properties is important in development novel fast sources incoherent illumination, single photon emitters for quantum optical applications, laser physics, and de-excitation electronic states leading photodegradation organic materials. Here, an emitter placed inside a hyperbolic metamaterial slab finite thickness comprised array gold nanorods, we experimentally...
Plasmonic technology relies on the coupling of light to surface electromagnetic modes smooth or structured metal surfaces. While some applications utilise resonant nature polaritons, others require broadband characteristics. We demonstrate unidirectional and plasmonic antennas with large acceptance angles based chirped gratings. Near-field optical measurements have been used visualise excitation plasmon polaritons by such aperiodic structures. These weakly crystals allow formation a trapped...
Hyperbolic plasmonic metamaterials are important for designing sensing, nonlinear, and emission functionalities, which are, to a large extent, determined by the epsilon-near-zero behaviour observed close an effective plasma frequency of metamaterial. Here, we describe method tuning gold nanorod-based metamaterial throughout visible near-infrared spectral ranges. These metamaterials, fabricated two-step anodization in selenic acid chemical post-processing, consist nanorods with diameters...