title: Evolutionary optimization of optical antennas.
abstract: The design of nanoantennas has so far been mainly inspired by radio-frequency technology. However, the material properties and experimental settings need to be reconsidered at optical frequencies, which would entail the need for alternative optimal antenna designs. Here we subject a checkerboard-type, initially random array of gold cubes to evolutionary optimization. To illustrate the power of the approach, we demonstrate that by optimizing the near-field intensity enhancement, the evolutionary algorithm finds a new antenna geometry, essentially a split-ring-two-wire antenna hybrid that surpasses by far the performance of a conventional gap antenna by shifting the n=1 split-ring resonance into the optical regime.
authors.affiliation: Nano-Optics & Biophotonics Group, Department of Experimental Physics, Röntgen Research Center for Complex Materials, Physics Institute, University of Würzburg, Germany.
authors.forename: Thorsten
authors.initials: T
authors.lastname: Feichtner
authors.forename: Oleg
authors.initials: O
authors.lastname: Selig
authors.forename: Markus
authors.initials: M
authors.lastname: Kiunke
authors.forename: Bert
authors.initials: B
authors.lastname: Hecht