Fig. 1: Plasmonic antennas from heavily doped germanium.
From: Plasmonic mid-infrared third harmonic generation in germanium nanoantennas
a The complex dielectric function of a heavily doped germanium film extracted from b, the reflectivity spectrum. c A scanning electron micrograph of a single germanium double-rod antenna on a silicon substrate with an arm length of 3.5 µm, a thickness of 700 nm and a gap width of 300 nm
