Nanoantennas can tailor light-matter interaction for optical communication, sensing, and spectroscopy. Their design is inspired by radio-frequency rules which partly break down at optical frequencies. Here we find unexpected nanoantenna designs exhibiting strong light localization and enhancement by using a general and scalable evolutionary algorithm based on FDTD simulations that also accounts for geometrical fabrication constraints. The resulting nanoantennas are "printed" directly by focused-ion beam milling and their fitness ranking is val- idated experimentally by two-photon photoluminescence. We find the best antennas’ operation principle deviating from that of classical radio wave-inspired designs. Our work sets the stage for a widespread application of evolutionary optimization in nano photonics.

Opt. Express

Feichtner, T, Selig, O, & Hecht, B. (2017). Plasmonic nanoantenna design and fabrication based on evolutionary optimization. Opt. Express, 25(10, Article number: 10828), 1–15. doi:10.1364/OE.25.010828