Optimization of plasmonic bowtie nanoantenna design and fabrication with swarm algorithm proximity effect correction

An optimally designed bowtie antenna produces an extremely concentrated electric field and correspondingly large Purcell enhancement of photon emission rate for quantum dots or dye molecules. Optimization of emission at desired wavelengths is usually achieved using electromagnetic solvers implementing finite element modeling (FEM). Actual nanofabrication, however, involving intricate e-beam lithography, etching, and metallization steps, often produces antennas that deviate from the desired shape. To reduce distortion of antennas produced by electron-beam lithography (EBL), an accurate prediction must be made for the resulting shape created from a given input geometry and dosing. In this work, a custom Proximity Effect Correction Software (PECS) with a Particle Swarm Optimization (PSO) algorithm has been developed and used to more accurately fabricate plasmonic nanoantennas. To further maximize enhancement, the results of the PECS have been used iteratively with FEM simulation in the PSO process to produce antennas with demonstrably high enhancement of photon emission at the target wavelength.