Nanoring structure, spacing, and local dielectric sensitivity for plasmonic resonances in Fano resonant square lattices.

Lattices of plasmonic nanorings with particular geometries exhibit singular, tunable resonance features in the infrared. This work examined effects of nanoring inner radius, wall thickness, and lattice constant on the spectral response of single nanorings and in Fano resonant square lattices, combining use of the discrete and coupled dipole approximations. Increasing nanoring inner radius red-shifted and broadened the localized surface plasmon resonance (LSPR), while wall thickness modulated the LSPR wavelength and decreased absorption relative to scattering.

Tunable peptoid microspheres: effects of side chain chemistry and sequence.

Peptoids are a versatile family of oligomeric synthetic molecules that can be customized for many applications. The submonomer solid-phase synthesis of peptoids allows for quick and inexpensive manufacturing and the selection of side chains is nearly limitless. In addition, peptoids that include chiral, aromatic side chains form stable helical secondary structure that leads to the potential for the formation of supramolecular assemblies.

Rate-limited electroless gold thin film growth: a real-time study.

Time-resolved, in situ spectroscopy of electroless (EL) gold (Au) films combined with electron microscopy showed that the deposition rate increased up to two-fold on surfaces swept by the bulk flow of adjacent fluid at Reynolds numbers less than 1.0, compared to batch immersion. Deposition rates from 5.

Gold nanoparticles reduced in situ and dispersed in polymer thin films: optical and thermal properties.

Optical and thermal activity of plasmon-active nanoparticles in transparent dielectric media is of growing interest in thermal therapies, photovoltaics and optoelectronic components in which localized surface plasmon resonance (LSPR) could play a significant role. This work compares a new method to embed gold nanoparticles (AuNPs) in dense, composite films with an extension of a previously introduced method. Microscopic and spectroscopic properties of the two films are related to thermal behavior induced via laser excitation of LSPR at 532 nm in the optically transparent dielectric.

Enhanced uniformity in arrays of electroless plated spherical gold nanoparticles using tin presensitization.

Gold nanoparticle arrays created with electroless gold plating provide a unique means of transforming nanocylinders usually formed in electron beam lithography to spherical nanoparticles. Alone, electroless gold plating is not selective to the substrate and results in the formation of a gold film on all exposed surfaces of an electron beam patterned sample, including the electron resist. Undesired gold plating occurred near patterned features on the substrate surface, which was reduced by increasing post-spin-coat cure time.

Tapered optical fibers designed for surface plasmon resonance phase matching.

Combining a modified two-step chemical etch method with equations to predict etch parameters and photon-plasmon phase-matching resulted in single-mode tapered optical fibers (TOFs) to optimize electromagnetic field enhancement. The phase-matching equation was used to identify the angle of incidence near the TOF cutoff radius at which surface plasmon resonance (SPR) is maximized. The axisymmetric Young-Laplace equation was used to predict the angle of incidence from the fabrication of a TOF via chemical etching.