Dispersive ground plane core shell type optical monopole antennas fabricated with electron beam induced deposition

We present the bottom-up fabrication of dispersive silica core, gold cladding ground plane optical nanoantennas. The structures are made by a combination of electron-beam induced deposition of silica and sputtering of gold. The antenna lengths range from 300 to 2100 nm with size aspect ratios as large as 20. The angular emission patterns of the nanoantennas are measured with angle-resolved cathodoluminescence spectroscopy and compared with finiteelement
methods. Good overall correspondence between the the measured and calculated
trends is observed. The dispersive nature of these plasmonic monopole antennas makes their radiation profile highly tunable.