Metamaterials have revolutionized the research in conventional electromagnetics. They display unique properties which can be used for the manipulation of electromagnetic waves in unexpected ways. In this research, a diamond nano-antenna is designed and optimized using the CST Microwave Studio, which uses Finite Difference Time Domain (FDTD) method. The designed unit cell shows high polarization conversion rates (PCR) for ultraviolet (UV) frequencies (especially the UV-B band) whilst covering Panchatram-Berry (PB) phase. The unit cell is then used to design metasurfaces that generate light beams carrying Orbital Angular Momentum (OAM) of different orders. Through the design of two dimensional metamaterial surfaces, the behavior of electromagnetic beams can be changed on sub-wavelength scale. This has led to a number of applications related to nanotechnology. A vortex beam carries Orbital Angular Momentum (OAM) which has played a vital role in increasing the bandwidth and data rate of optical communication systems. Therefore, OAM beams having different topological charges have been generated at 294 nm to propose an improvement in Free Space Optical (FSO) communication. Optical links also function as a suitable substitute for applications where Radio Frequency (RF) communications may not be effective. The proposed theoretical model is expected to open new horizons in optical communication by incorporating the use of nanoscale devices with high efficiencies in the ultraviolet regime.
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