We demonstrate a strong, 5-fold enhancement of the radiative decay rate from highly efficient fluorescent dye molecules around resonant optical nanoantennas. The plasmonic modes individual gold dimer antennas are tuned by particle length and antenna gap, providing control over both spectral resonance position near-field mode profile nanoantenna. Resonant nonradiative rates is observed, resulting in an increase internal quantum efficiency 40% up to 53% for single antennas, 59% clusters. This...

We experimentally investigate the optical properties of layers InP, Si, and GaP nanowires, relevant for applications in solar cells. The nanowires are strongly photonic, resulting a significant coupling mismatch with incident light due to multiple scattering. identify design principle effective suppression reflective losses, based on ratio nondiffusive absorption diffusive scattering lengths. Using this principle, we demonstrate successful hemispherical diffuse reflectance InP below that...

Abstract Phase‐change materials (PCMs) are seeing tremendous interest for their use in reconfigurable photonic devices; however, the most common PCMs exhibit a large absorption loss one or both states. Here, Sb 2 S 3 and Se demonstrated as class of low loss, reversible alternatives to standard commercially available chalcogenide PCMs. A contrast refractive index Δ n = 0.60 0.77 is reported, while maintaining very losses ( k < 10 −5 ) telecommunications C‐band at 1550 nm. With stronger...

Deep learning in the context of nano-photonics is mostly discussed terms its potential for inverse design photonic devices or nanostructures. Many recent works on machine-learning are highly specific, and drawbacks respective approaches often not immediately clear. In this review we want therefore to provide a critical capabilities deep progress which has been made so far. We classify different learning-based at higher level as well by their applications critically discuss strengths...

We demonstrate experimentally picosecond all-optical control of a single plasmonic nanoantenna embedded in indium tin oxide (ITO). identify response the antenna–ITO hybrid system, which is distinctly different from transient bleaching observed for gold antennas on nonconducting SiO2 substrate. Our experimental results can be explained by large free-carrier nonlinearity ITO, enhanced plasmon-induced hot-electron injection into conductive oxide. The combination tunable hybrids with nanoscale...

Deep artificial neural networks are powerful tools with many possible applications in nanophotonics. Here, we demonstrate how a deep network can be used as fast, general purpose predictor of the full near-field and far-field response plasmonic dielectric nanostructures. A trained is shown to infer internal fields arbitrary three-dimensional nanostructures orders magnitude faster compared conventional numerical simulations. Secondary physical quantities derived from learning predictions...

Optical solar reflector smart radiators are able to control the temperature of spacecraft. This work demonstrates a novel optical using patterned thermo-chromic VO2 plasmonic meta-surface design. The combines induced phase transition with resonances resulting in significant enhancement infrared absorption. enhanced absorption obtained at reduced coverage results superior emittance tunability Δε and lower absorptance α compared corresponding thin-film reflector. An 0.48 is for meta-reflector...

An ultralow-loss optical phase change material enables reversible programming of the flow light in silicon photonics.

Abstract Smart radiative cooling devices based on thermochromic materials such as vanadium dioxide (VO 2 ) are of practical interest for temperature regulation and artificial homeostasis, i.e., maintaining stable equilibrium conditions survival, both in terrestrial space applications. In traditional solar reflector configurations, absorption the VO layer is a performance limiting factor due to multiple reflections sunlight stack. Here, we demonstrate visually transparent, smart radiator...

Increasing the evaporation zone inside solar distiller (SD) is a pivotal method for augmenting its freshwater production. Hence, in this work, newly designed prismatic absorber basin covered by linen wicks was utilized instead of conventional flat to increase surface area vaporization double-slope (DSSD). Meanwhile, further enhancement modified DSSD performance, dual parallel spraying nozzles are incorporated underneath glass cover as saltwater feed supply minimize thickness film on wick,...

A broad-band and omnidirectional antireflection coating consisting of semiconductor nanowires is fabricated. The reflection reduced due to a graded refractive index, which achieved by certain nanorod-length distribution cylindrical conically shaped rods. An increased transmission and, accordingly, are demonstrated for the visible near-infrared parts spectrum.

We successfully demonstrate surface-enhanced infrared spectroscopy using arrays of indium tin oxide (ITO) plasmonic nanoantennas. The ITO antennas show a strongly reduced plasmon wavelength, which holds promise for ultracompact antenna and extremely subwavelength metamaterials. strong confinement cross section allows to be integrated at high densities with no loss in performance due long-range transverse interactions. By further reducing the spacing arrays, we access regime near field...

In this work we demonstrate a DNA biosensor based on fluorescence resonance energy transfer (FRET) between NaYF4:Yb,Er nanoparticles and graphene oxide (GO). Monodisperse with mean diameter of 29.1 ± 2.2 nm were synthesized coated SiO2 shell 11 nm, which allowed the attachment single strands DNA. When these DNA-functionalized NaYF4:Yb,Er@SiO2 in proximity GO surface, π–π stacking interaction nucleobases sp2 carbons induced FRET quenching due to overlap emission absorption spectrum GO. By...

The ultrafast nonlinear optical response of a single metal nanoparticle is investigated by combining high-sensitivity femtosecond pump-probe setup with spatial modulation microscope. Experiments are performed on 20 and 30 nm silver nanospheres, in situ characterized via their linear extinction spectrum. measured transient permits investigation the electron-phonon energy transfer time nanoparticle. Its dependence electronic temperature quantitatively interpreted using two-temperature model.

We propose and explore theoretically a new concept of ultrafast optical switches based on nonlinear plasmonic nanoantennas. The antenna nanoswitch operates the transition from capacitive to conductive coupling regimes between two closely spaced metal nanorods. By filling gap with amorphous silicon, progressive antenna-gap loading is achieved due variations in free-carrier density semiconductor. Strong modification response observed both far-field local near-field intensity. large modulation...

The spectrally- and polarization-resolved absorption cross-sections of a single gold nanorod have been investigated using the spatial modulation spectroscopy technique. ensemble its optical features, that is, longitudinal transverse surface plasmon resonances interband absorption, has quantitatively characterized. results are compared with numerical simulations discrete dipole approximation finite element method, yielding information on size shape.

Optical solar reflectors are devices that combine high reflection for visible wavelengths with a strong emissivity in the infrared. Compared to conventional rigid quartz tiles used on spacecraft since 1960s, thin-film solutions can offer significant advantage weight, assembly, and launch costs. Here, we present metasurface-based approach using an Al-doped ZnO (AZO) transparent conducting oxide as infrared plasmonic material. The AZO is patterned into metasurface achieve broad resonances...

We demonstrate that highly tunable nanowire arrays with optimized diameters, volume fractions, and alignment form one of the strongest optical scattering materials to date. Using a new broad-band technique, we explore strength nanowires by varying systematically their diameter on substrate. identify strong Mie-type internal resonances which can be tuned over entire visible spectrum. The tunability opens up exciting prospects for fundamental applied research ranging from random lasers solar...

The optical resonances of individual plasmonic dimer antennas are investigated using confocal darkfield spectroscopy.Experiments on an array with varying arm lengths and interparticle gap sizes show large spectral shifts the plasmon modes due to a combination geometrical hybridization.The coupled-dimer considerably broadened compared those single nanorods, which is attributed superradiant damping coupled antenna modes.The scattering spectra electrodynamic model calculations that demonstrate...

The interactions between skin and colloidal gold nanoparticles of different physicochemical characteristics are investigated. By systematically varying the charge, shape, functionality nanoparticles, nanoparticle penetration through layers is assessed. evaluated both qualitatively quantitatively using a variety complementary techniques. Inductively coupled plasma optical emission spectrometry (ICP-OES) used to quantify total number particles which penetrate structure. Transmission electron...

Abstract The interactions between noncancerous, primary endothelial cells and gold nanoparticles with different morphologies but the same ligand capping are investigated. incubated nanospheres, nanorods, hollow spheres, core/shell silica/gold nanocrystals, which coated monocarboxy (1‐mercaptoundec‐11‐yl) hexaethylene glycol (OEG). Cell viability studies show that all types of particles noncytotoxic. number taken up by is estimated using inductively coupled plasma (ICP), found to differ...

The design of nanoparticulate systems which can perform multiple synergistic functions in cells with high specificity and selectivity is great importance applications. Here we combine recent advances DNA-gold nanoparticle self-assembly sensing to develop gold dimers that are able multiplexed within a cellular environment. These sense two mRNA targets simultaneously or independently deliver one DNA-intercalating anticancer drugs (doxorubicin mitoxantrone) live cells. Our study focuses on the...

The development of new sensors for the accurate detection biomarkers in biological fluids is utmost importance early diagnosis diseases. Next to advanced laboratory techniques, there a need relatively simple methods which can significantly broaden availability diagnostic capability. Here, we demonstrate successful application sensor platform based on graphene oxide and upconversion nanoparticles (NPs) specific mRNA-related oligonucleotide markers complex fluids. combination near-infrared...