Novel EM Effects
Daniel Peter Ceperley and Andrew R. Neureuther
Preliminary investigations into plasmonic nanocrystal-based surface-enhanced Raman spectroscopy sensors demonstrate significant simulation challenges and motivate the next-generation TEMPEST. Simulations of surface plasmon concentrators (important for electron sources and near-field probes) show that surface geometry is crucial and can be tuned through simulation. Sub-wavelength grating reflectors will play a key role in tunable vertical cavity surface emitting lasers and initial investigations have shown that TEMPEST is an effective tool for grating analysis. During investigations into the Terrestrial Planet Finder Coronagraph, surface plasmons were discovered on diffraction masks, motivating the current work. Additionally, severe manufacturing roughness was observed on mask sidewalls and was modeled in TEMPEST.
Figure 1: Scattering pattern generated by a surface plasmon interacting with a silver bar. Insulation between the bar and the substrate is critical for radiation coupling.
Figure 2: Near-field pattern of light passing through an arrangement of six carbon nanotubes. The extrememly small size of the nanotubes resulted in numerical instabilities which manifested as unphysical ripples in the scattering pattern around the walls of each nanotube.