Surface plasmon-based nanopatterning assisted by gold nanospheres.

A pulsed laser is used to produce surface plasmon excitation in a monolayer of gold (Au) spheres to nanopattern a silicon substrate. An electrodynamic model accompanies the experimental data, based on the numerical solution to the complete Maxwell's equations including near- and far-field effects and reflection from the substrate. The Drude-employing finite-difference time-domain method describes the deformation and enhancement of the laser pulse around the boundary of a Au sphere and the resulting distribution of intensity incident upon the substrate. The effect of the incident laser angle on the plasmon generation and lithographic potential is studied.