UWB Dual-Vivaldi nano-antenna and load effect on the reflection properties

Dual-Vivaldi nanoantenna arrays were designed, fabricated and optically characterized in the infrared (IR) and visible regimes. The antenna arrays were characterized by measuring the scattered light at IR (1450-1640 nm) and visible (780 nm) spectral ranges. The radiation efficiency and the spectral response of the antennas were found to be in good agreement with numerical simulations. The results presented here demonstrate the extremely wide-band nature of the dual-Vivaldi antennas and the strong dependence of the scattering response on the load at the antenna terminals. These properties, as well as their many degrees of freedom for design, render the dual-Vivaldi antennas excellent candidates for optical sensing applications.