A circularly polarized super wideband transparent optical nanoantenna for advanced THz communication applications

This paper investigates a nano-scaled patch antenna in optical frequency range. The proposed nanoantenna consists of a circular patch of dimension 130 × 130 nm², placed on a glass substrate with thickness 112 nm. To protect the antenna against environmental jeopardies, a superstrate layer of dimensions 40 × 2.5 × 110.4 nm³ has been added. To enhance the performance of the antenna in terms of bandwidth and efficiency and to obtain circular polarization, multiple slots are added into the patch and ground plane of the proposed nanoantenna. The suggested antenna resonates at 182 THz with an impedance bandwidth of about 47 THz (160–207 THz) and a minimum radiation efficiency of 96.54% throughout the entire operating band. The operating bandwidth of the designed nano antenna corresponds to a wavelength range of 1449–1875 nm which covers the entire wavelength of the third optical communication window centered at 1550 nm. Besides, the proposed antenna is circularly polarized which make it very interesting in wireless communication system because it has the advantage to emit the electromagnetic radiation in a corkscrew fashion which allows efficient transmission to the receiver. The proposed antenna covers the telecom optical communication wavelength bands, S-band (1460–1530 nm), C-band (1530–1565 nm), and L-band (1565-1625 nm) in the operating range of 160 THz–207 THz. The proposed nanoantenna with circular polarization might be useful for various integrated components and variety of applications such as optical communication, nano photonics, biosensing, and spectroscopy and could play an essential role in progress of plasmonic sensors.