Shimon Elkabetz | Searcharxiv

arXiv2020

Sum frequency generation from touching wires: A transformation optics approach

We employ transformation optics to study analytically nonlinear wave mixing from a singular geometry of touching plasmonic wires. We obtain the analytic solution of the near-field and complement it with a solution of the far-field properties. We find, somewhat surprisingly, that optimal efficiency (in both regimes) is obtained for the degenerate case of the Second-harmonic generation. We exploit the analytic solution obtained to trace this behaviour to the spatial overlap of the input fields near the geometric singularity.

physics.optics↗

arXiv2020

Optimization of second-harmonic generation from touching plasmonic wires

We employ transformation optics to optimize the generic nonlinear wave interaction of second-harmonic generation from a pair of touching metallic wires. We demonstrate a 10 orders of magnitude increase in the second-harmonic scattering cross-section by increasing the background permittivity and a 5 orders of magnitude increase in efficiency with respect to a single wire. These results have clear implications for the design of nanostructured metallic frequency-conversion devices. Finally, we exploit our analytic solution of a non-trivial nanophotonic geometry as a platform for performing a critical comparison of the strengths, weaknesses and validity of other prevailing theoretical approaches previously employed for nonlinear wave interactions at the nanoscale.

physics.optics↗