Unconventional Optical Phased Array Design for Next-Generation Wireless Systems

This thesis focuses on the design, analysis, and performance characterization of thinned optical phased arrays (OPAs), aiming to achieve high-quality far-field beamforming and near-field focusing through a multi-objective (MO) optimization framework. The method addresses the challenge of selecting which antenna elements should be retained or removed from a fully populated linear OPA arranged on a uniform grid, while preserving or enhancing key radiation or focusing performance such as low sidelobe levels (SLL) and narrow half-power beamwidth (HPBW). Furthermore, for far-field applications, an analytical modeling approach is developed, where the radiation characteristics of the waveguide grating antenna (WGA) are integrated with the linear thinned OPA synthesis process, resulting in an overall radiation pattern and enabling two-dimensional beam scanning. The study also explores structural improvements of the WGA elements to further suppress sidelobe levels along the antenna axis. Additionally, the near-field focusing performance is analyzed in detail, both on the focal plane and along the focal axis. A comprehensive set of numerical experiments is conducted to evaluate the feasibility and efficiency of the proposed approach in solving the thinned OPA design problem.