  We determine and use a minimal set of numerical simulations to create a
simplified model for the spectral response of nanoantennae with respect to
their geometric and modeling parameters. The simplified model is then used to
rapidly obtain best-fit modeling parameters to match experimental results,
accurately predict the spectral response for various geometries, and inversely
design antennae to have a desired performance. This method is structure and
model independent, and is applied here to both nanoantenna pair arrays and
strips modeled using a 3D finite-element method and 2D spatial harmonic
analysis, respectively. Typical numerical simulations may need hours per model,
whereas this method, after the initial time to obtain a baseline set of
simulations, requires only seconds to analyze and generate spectra for new
geometries.
