Metal nanostructures provide extreme focusing of optical energy that is limited fundamentally by quantum tunneling. We directly probe the onset tunneling regime observed a sharp reduction in local field intensity subnanometer self-assembled monolayer gaps using third harmonic generation. Unlike past works have inferred limits from far-field spectra, this nonlinear measurement sensitive to near-field as power. calculate corrected model and find good quantitative agreement with measured...

Recently, self-assembled monolayers (SAMs) have been used for plasmonic rulers to measure the nonlocal influence on Au nanoparticle - metal film resonance wavelength shift and probe ultimate field enhancement. Here we examine of surface roughness this ruler in regime by comparing shifts as-deposited ultra-flat films. It is shown that larger films, suggesting there not saturation from effects previously reported spacer range 0.7 nm 1.6 nm. We attribute planarization films thinner SAMs, as...

The influence of gap plasmons in the third-harmonic generation annular and H-shaped aperture arrays has been investigated. Surprisingly, maximum third harmonic ring structures is not from smallest gap, but rather appears for a 14 nm. We interpret this result terms resonant plasmonic antenna design to match scattering absorption cross sections. Unlike aperture, continuous gold apertures, like H-structure, achieve 0.45% conversion efficiency 2 mW/μm2 CW pump power 100 fs pulse, which 9 times...

Single-photon sources are required for quantum technologies and can be created from individual atoms atom-like defects. Erbium ions produce single photons at low-loss fiber optic wavelengths, but they have low emission rates, making them challenging to isolate reliably. Here, we tune the size of gold double nanoholes (DNHs) enhance erbium emitters, achieving 50× enhancement over rectangular apertures previously demonstrated. This produces enough show nanocrystals wavelengths not seen in our...

We measure third harmonic generation (THG) as a function of infrared fundamental wavelength for gold nanoparticles over film. An order magnitude enhancement in THG is found at ~2.5 eV. ensure that this away from plasmonic resonances, so it may be attributed directly to the ultrafast third-order susceptibility gold. Using simple relation between linear and susceptibilities conjunction with response gold, we show experimental results agree well interband transitions. This result interesting...

Abstract Ultrafast laser-induced magnetization dynamics in ferromagnetic thin films were measured using a femtosecond Ti:sapphire laser pump-probe magneto-optic Kerr effect setup. The of plasmon resonance on the transient was investigated by drop-coating with dimensionally-tuned gold nanorods supporting longitudinal surface near central wavelength pump laser. With ~4% nanorod areal coverage, we observe >50% increase demagnetization signal nanorod-coated samples at fluences order 0.1 mJ/cm...

Nanohole optical tweezers have been used by several groups to trap and analyze proteins. In this work, we demonstrate that it is possible create high-performance double nanohole (DNH) substrates for trapping proteins without the need any top-down approaches (such as electron microscopy or focused-ion beam milling). Using polarization analysis, identify DNHs well determine their orientation then use them trapping. We are also able other hole configurations, such single, trimers clusters....

A single step process of integrating a resonantly tuned silver nanoparticle into photonic crystal nanobeam cavities fabricated by focused ion beam milling is presented. Even though the quality factor reduced 20, emission peak at cavity resonance enhanced 5-fold with respect to without metal nanoparticle. The fluorescence also compared before and after etching away Experimental factors wavelength shifts are found agree reasonably well simulation values. These results promising for future...

We quantified an exogenous cancer biomarker, Acetyl amantadine (AcAm), directly from urine solution using surface enhanced Raman spectroscopy (SERS), achieving a clinically relevant limit of detection.

In this work we report a new thermochemical method for the synthesis of ZnS:Mn nanocrystals. Zn(NO(3))(2) and Na(2)S(2)O(3) were used as precursors Mn(NO(3))(2) was source impurity. Thioglycerol (TG,C(3)H(8)O(2)S) also capping agent catalyst reaction. is heat sensitive material which releases S species upon heating. Consequently, reaction proceeds in temperatures higher than room temperature. The done two steps. first step, heated at 96 degrees C an hour without TG. second TG injected to...

The Einstein-de Haas (EdH) effect is a consequence of angular momentum conservation wherein physical rotation magnetic body results from change in magnetization. A micromechanical resonator supporting ladder resonances used to explore the inherent frequency dependence torque resulting this thin-film permalloy sample, utilizing cavity optomechanical readout. Giant EdH torques are found at gyrotropic resonance permalloy, which overlaps high-order mechanical sensor.

We report the plasmon hybridization between silver nanoprisms and a thin gold film as means to tune resonance achieve enhanced optical second harmonic generation. The enhances counts by nearly three orders of magnitude when varying spacer layer film. Finite-difference time-domain calculations agree within factor 2 with experimental findings in terms predicted enhancement factor. This approach is promising for future applications, including multi-photon lithography nonlinear sensing using...

Abstract Significant new functionality is reported for torsion mechanical tools aimed at full magnetic characterizations of both spin statics and dynamics in micro- nanostructures. Specifically, two orthogonal torque directions are monitored the results co-analyzed to separate moment susceptibility contributions torque, as desired characterization anisotropic three-dimensional structures. The approach demonstrated through application shape microstructural disorder-induced anisotropies...

The strong nonlinear optical response of two-dimensional materials has applications in bioimaging and integrated information processing; however, past experiments were on diffraction limited samples or required intense pulsed lasers, which is a detriment to potential due cost, power complexity. Here we show that second harmonic generation can be achieved from single subwavelength material nanoflakes smaller than the limit using plasmonic tweezer with low-power (down 3 mW) laser diode...

The influence of the localized surface plasmon resonance on magneto-optical Kerr effect (MOKE) was investigated in Ni80Fe20 thin films coated with gold nanorods. nanorods are dimensionally tuned to support near incident laser frequency. A significant enhancement response is observed, which MOKE signal increased by over 40% compared reference films. spectral dependence signals exhibits maximum centered around longitudinal wavelength Finite-difference time-domain modeling confirms that...

We probe the acoustic vibrations of silver nanoprisms and gold nano-octahedrons in aqueous solution with four-wave mixing. The nonlinear optical response shows two vibrational modes: an in-plane mode vertexial expansion contraction; extensional longitudinal transverse contraction. particles were also analyzed electron microscopy resonance frequencies then calculated by finite element analysis, showing good agreement experimental observations. fit theoretical approximations, which show...

We investigate the switching of a gap plasmon tunnel junction between conducting and insulating states. Hysteresis is observed in second third harmonic generation power dependence, which arises by thermally induced disorder (“melting”) two-carbon self-assembled monolayer an ultraflat gold surface metal nanoparticles. The hysteresis for variety nanoparticle sizes, but not larger junctions where there no appreciable tunneling. By combining quantum corrected finite-difference time-domain...

Antenna performance can be described by two fundamental parameters: directivity and radiation efficiency. Here, we demonstrate nanoantenna designs in terms of improved directivity. Performance the antennas is demonstrated Raman scattering experiments. The radiated beam directed out plane using a ground reflector for easy integration with commercial microscopes. Parasitic elements parabolic waveguide nanoantennas are explored. were fabricated series electron evaporation steps focused ion...

We demonstrate the application of polystyrene-functionalized gold nanorods (AuNRs) as a platform for surface enhanced Raman scattering (SERS) quantification exogenous cancer biomarker Acetyl Amantadine (AcAm). utilize hydrophobicity polystyrene attached to AuNR capture hydrophobic AcAm from solution, followed by drying and detection using SERS. achieve limit 16 ng/mL this platform. This result shows clinical potential low-cost early detection.

Upconverted light from nanostructured metal surfaces can be produced by harmonic generation and multi-photon luminescence; however, these are very weak processes require extremely high field intensities to produce a measurable signal. Here we report on bright emission, 5 orders of magnitude greater than generation, that seen tunnel junctions believe is due light-induced inelastic tunneling emission. Like which was recently reported have 2% conversion efficiency per event, the emission...

Using light to measure an object’s motion is central operating mechanical sensors that probe forces and fields. Cavity optomechanical systems embed resonators inside optical resonators. This enhances the sensitivity of measurements, but only if resonator does not spoil properties cavity. For example, cavity detection made from optically absorbing materials, or whose geometry possess suitable spatial symmetry, challenging. Here we demonstrate a system overcomes challenges in measuring...

We demonstrate a parabolic reflector nanoantenna as structure for directivity-enhanced Raman scattering (DERS). This antenna consists of nanoscale paraboloid shaped Au and an Ag nanoprism feed element. experimentally test this obtain 22× enhancement to the signal from structures with planar reflectors, estimate 1100× surface-enhanced (SERS) alone. A comprehensive finite-difference time-domain simulation is used model field intensity in nanoantenna, confirming its better coupling between...

We demonstrate tuning of the plasmonic resonance silver nanoprisms by coupling to a thin gold film (i.e., through plasmon hybridization). Altering thickness dielectric spacer layer between and is convenient way shift resonant wavelength, from 610 nm 850 demonstrated, both with numerical calculations experiment. This has applications for second harmonic generation, two photon lithography, spectroscopy.

We present the simulation results, fabrication and measurements of a Si <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> N xmlns:xlink="http://www.w3.org/1999/xlink">4</sub> nanobeam cavity as first step obtaining enhanced single photon emission from quantum emitters in photonic crystal incorporating metal nanoparticle. The is designed to resonate at operating wavelength CdSe dot emitter. use focused ion beam (FIB) milling one process...