Enhancing Diamond Color Center Fluorescence via Optimized Configurations of Plasmonic Core-Shell Nanoresonator Dimers.

Numerical optimization of silica-metal core-shell nanoresonator dimer geometries was realized to maximize the fluorescence of the NV and SiV diamond color centers. The configurations combine the advantages stemming from the elongation and reduced metal volume of hollow spheroids and the wide tunability and good antenna efficiency due to hybridization of composite modes on the core-shell dimers. The optimized coupled dimers sustain plasmonic modes that maximize the fluorescence by ensuring the simultaneous enhancement of excitation and emission.

Crater formation and deuterium production in laser irradiation of polymers with implanted nano-antennas.

Recent validation experiments on laser irradiation of polymer foils with and without implanted golden nanoparticles are discussed. First we analyze characteristics of craters, formed in the target after its interaction with the laser beam. Preliminary experimental results show significant production of deuterons when both the energy of laser pulse and concentration of nanoparticles are high enough.

The Effect of Femtosecond Laser Irradiation and Plasmon Field on the Degree of Conversion of a UDMA-TEGDMA Copolymer Nanocomposite Doped with Gold Nanorods.

In this work, the effects of femtosecond laser irradiation and doping with plasmonic gold nanorods on the degree of conversion () of a urethane dimethacrylate (UDMA)-triethylene glycol dimethacrylate (TEGDMA) nanocomposite were investigated. The UDMA-TEGDMA photopolymer was prepared in a 3:1 weight ratio and doped with dodecanethiol- (DDT) capped gold nanorods of 25 × 75 or 25 × 85 nm nominal diameter and length. It was found that the presence of the gold nanorods alone (without direct plasmonic excitation) can increase the of the photopolymer by 6-15%.

Plasmonically Enhanced Superradiance of Broken-Symmetry Diamond Color Center Arrays Inside Core-Shell Nanoresonators.

Superradiance was demonstrated in broken-symmetry arrays of SiV diamond color centers embedded into concave plasmonic nanoresonators. The coupled configurations, including the diamond-silver (bare) and diamond-silver-diamond (coated) nanoresonators' geometry parameters as well as the emitters' azimuthal orientation and distance from the metal, were numerically optimized. An objective function consisting of the total fluorescence enhancement multiplied by the corrected emission quantum efficiency was used to design nanoresonators that promote superradiance.

Active Individual Nanoresonators Optimized for Lasing and Spasing Operation.

Plasmonic nanoresonators consisting of a gold nanorod and a spherical silica core and gold shell, both coated with a gain layer, were optimized to maximize the stimulated emission in the near-field (NF-c-type) and the outcoupling into the far-field (FF-c-type) and to enter into the spasing operation region (NF-c*-type). It was shown that in the case of a moderate dye concentration, the nanorod has more advantages: smaller lasing threshold and larger slope efficiency and larger achieved intensities in the near-field in addition to FF-c-type systems' smaller gain and outflow threshold, earlier dip-to-peak switching in the spectrum and slightly larger far-field outcoupling efficiency. However, the near-field (far-field) bandwidth is smaller for NF-c-type (FF-c-type) core-shell nanoresonators.

Few-cycle localized plasmon oscillations.

The generation of few-cycle laser pulses proved to be a key enabling technology in strong-field physics and ultrafast science. The question naturally arises whether one can induce few-cycle localized plasmon oscillations in optical near-fields. Here, we perform a comparative study of different plasmonic nanoresonators illuminated by few-cycle pulses.

Superradiant diamond color center arrays coupled to concave plasmonic nanoresonators.

Superradiantly enhanced emission of SiV diamond color centers was achieved via numerically optimized concave plasmonic nanoresonators. Advantages of different numbers of SiV color centers, diamond-silver (bare) and diamond-silver-diamond (coated) core-shell nanoresonator types, spherical and ellipsoidal geometries were compared. Indistinguishable superradiance is reached via four color centers, which is accompanied by line-width narrowing except in a coated ellipsoidal nanoresonator that outperforms its bare counterpart in superradiance.

Improved emission of SiV diamond color centers embedded into concave plasmonic core-shell nanoresonators.

Configuration of three different concave silver core-shell nanoresonators was numerically optimized to enhance the excitation and emission of embedded silicon vacancy (SiV) diamond color centers simultaneously. Conditional optimization was performed to ensure ~20-30-40 and 50% apparent quantum efficiency (cQE) of SiV color centers. The enhancement spectra, as well as the near-field and charge distribution were inspected to uncover the underlying nanophotonical phenomena.

Plasmonic structure integrated single-photon detector configurations to improve absorptance and polarization contrast.

Configurations capable of maximizing both the absorption component of system detection efficiency and the achievable polarization contrast were determined for 1550 nm polarized light illumination of different plasmonic structure integrated superconducting nanowire single-photon detectors (SNSPDs) consisting of p = 264 nm and P = 792 nm periodic niobium nitride (NbN) patterns on silica substrate. Global effective NbN absorptance maxima appear in case of p/s-polarized light illumination in S/P-orientation (γ = 90°/0° azimuthal angle) and the highest polarization contrast is attained in S-orientation of all devices. Common nanophotonical origin of absorptance enhancement is collective resonance on nanocavity gratings with different profiles, which is promoted by coupling between localized modes in quarter-wavelength metal-insulator-metal nanocavities and laterally synchronized Brewster-Zenneck-type surface waves in integrated SNSPDs possessing a three-quarter-wavelength-scaled periodicity.