Design and modeling of a tunable optical antenna enabled by a micromachined actuator

A MEMS-based tunable optical nanoantenna is described. The optical performance of the tunable antenna has been investigated using rigorous finite difference time domain (FDTD) method. It reveals that peak wavelengths and local field enhancements are largely affected by the size and shape of the bowtie antenna. The optical field can be drastically enhanced by reducing the gap size less than 30 nm which can easily be achieved by the MEMS system. Studies for field localization also shows possibility of bowtie antennas producing isotropic field patterns with an aspect ratio close to one, essential for full 2-D surface scanning purposes.