Optimizing the bowtie nano-antenna for enhanced purcell factor and electric field

Abstract

With the development of nano-optic technology, the optical nano-antenna has been widely used in the fields of novel light sources, high-sensitive biological sensors, nanometer lithography, and nano-optical imaging. The relationship between the structural parameters of the antenna and the Purcell factor is very important for engineering applications. The electric near field profile of the antenna was calculated and analyzed by using the finite-difference time-domain (FDTD) method, and the influence of the structural parameters on the Purcell factor and the electric field was thoroughly investigated. A careful comparison of bowtie antenna radiation characteristics with different structural parameters was carried out. The results show that the thickness, the length and the curvature radius have great effects on the Purcell factor and the optical antenna's electric near field. These findings are promising for improving the performance of the optical bowtie nano-antenna.