Torus-Shaped Quantum Plasmonic Nano-Antenna Array for Optical Near-Field Communication

The manuscript portrays the investigation of a quantum plasmonic gold torus nanodipole antenna on a zinc oxide dielectric substrate for optical near-field communication. Initially, the dispersive behavior of gold and zinc oxide materials at terahertz is demonstrated through Drude and Lorentz models to confirm the suitability of the material for the design of nano-antenna. The proposed torus nanodipole antenna is analyzed in detail using substrate, torus and feeding gap design parameters of the antenna to obtain the desired plasmon resonance characteristics for optical near-field communication. The minimal reflection of -50.50 dB is observed at 71.3 THz with a directivity of 1.91 dBi using a single nanodipole element. The torus nanodipole antenna array is proposed to enhance the directivity and gain of the torus nanodipole antenna. The directivities of 9.425 dBi, 12.63 dBi and 14.63 dBi and the gain of 7.69 dBi, 10.77 dBi and 13.3 dBi are observed for the 2x 2, 3 x 3 and 4 x 4 element nanodipole arrays, respectively. The circuit modeling for the torus nanostructure is proposed and validated using the finite integration technique.