Performance Evaluation of a Fractal Plasmonic Bowtie Nano-Antenna: Optical and Far-Field Properties

In the nano-antenna framework, in this work, we have proposed a fractal plasmonic bowtie nano-antenna (FPBNA) with three wings to maximize the coupling between higher and lower order modes. Hollow cavities of the bowtie nano-antenna support hybridization modes, both anti-bonding and bonding modes. In other words, the blue-shift in the hybridization modes results from an increase in the Sierpiński fractal iteration, which facilitates the minimization of hollow regions in fractals after each iteration. We have investigated both near-and-far field characteristics of the proposed FPBNA. We have investigated both near-and-far field characteristics of the proposed FPBNA. We have demonstrated that the near-field intensity of the FPBNA is tunable and adjustable by modifying geometrical and electromagnetic parameters and the incident wave. Furthermore, the FPBNA exhibits superior performance in terms of polarization independency, absorptance, and robustness against losses, compared to other available bowtie nano-antenna structures. In the far-field region, the FPBNA possesses very low-radiative characteristics, in the order of
$10^{-7}$
dB, as well as robustness to a variation of
$\phi$
angles.