Absorption enhancement by matching the cross-section of plasmonic nanowires to the field structure of tightly focused beams.

Nanostructured materials, designed for enhanced light absorption, are receiving increased scientific and technological interest. In this paper we propose a physical criterion for designing the cross-sectional shape of plasmonic nanowires for improved absorption of a given tightly focused illumination. The idea is to design a shape which increases the matching between the nanowire plasmon resonance field and the incident field.

Plasmonic resonance effects for tandem receiving-transmitting nanoantennas.

A nanoplasmonic "transceiver" was assembled to examine the efficiency of coupled plasmonic antennas and their resonance interactions. In particular, plasmonic focusing receiver antenna coupled to transmitting annular antenna having a short central plasmonic wire was measured. The receiver collected incoming radially polarized light and efficiently focused and coupled it to a rear side transmitter comprised of a short resonant plasmonic wire and annular aperture.

Plasmonic resonance scattering from silver nanowire illuminated by tightly focused singular beam.

We investigate scattering features of tightly focused singular beams by placing a cylindrical nanowire in the vicinity of a line phase singularity. Applying an illumination wavelength corresponding to silver cylinder plasmonic resonance, we compare the scattering response with that of a perfect conductor. The rigorous modeling employs a 2D version of the Richards-Wolf focusing method and the source model technique.

Efficient coupling and field enhancement for the nano-scale: plasmonic needle.

Theoretical demonstration of efficient coupling and power concentration of radially-polarized light on a conical tip of plasmonic needle is presented. The metallic needle is grown at the center of radial plasmonic grating, engraved in a metal surface. The electromagnetic field distribution was evaluated by Finite Elements and Finite-Difference-Time-Domain methods.

Singular beam microscopy.

Optical singularities are localized regions in a light field where one or more of the field parameters, such as phase or polarization, become singular with associated zero intensity. Singular beam microscopy exploits the fact that the strong variations of the optical field around the singularities are highly sensitive to changes in their neighborhood. As a consequence, analysis of the light field scattered from the object during a scanning process can yield useful information about the object features.