Omnidirectional beam steering using aperiodic optical phased array with high error margin.

Area of Science:

• Photonics and Optical Engineering
• Applied Physics
• Electrical Engineering

Background:

• Optical phased arrays (OPAs) are crucial for beam steering in applications like LiDAR and free-space communication.
• Existing OPA designs often face limitations in scan range, beam divergence, and manufacturing tolerances.
• Aperiodic designs offer potential advantages over traditional uniformly spaced arrays.

Purpose of the Study:

• To propose and design a novel aperiodic optical phased array (O-OPA) using a pattern-search-like algorithm.
• To achieve enhanced performance metrics including scan range, side-lobe level, beam width, and element pitch.
• To investigate the error tolerance of the designed aperiodic structure.

Main Methods:

• Development of a pattern-search-like algorithm for designing the aperiodic optical phased array.
• Simulation and analysis of a 128-element isotropic O-OPA.
• Characterization of key performance parameters: scan range, peak side-lobe level, minimum beam width, and mean pitch.
• Analysis of the relationship between machine error and side-lobe level.

Main Results:

• The designed O-OPA achieved a scan range of ± 82°, a peak side-lobe level of -14.34 dB, a minimum beam width of 0.062°, and a mean pitch of 9.75 μm.
• The O-OPA demonstrated the widest steering range, narrowest divergence, and largest mean pitch for 128 elements.
• Minimum pitch can exceed 2.67λ to prevent cross-coupling.
• The structure exhibits higher error tolerance compared to uniformly spaced counterparts.

Conclusions:

• The proposed pattern-search algorithm effectively designs high-performance aperiodic optical phased arrays.
• The developed O-OPA surpasses existing designs in key performance metrics, enabling advanced applications.
• The aperiodic design offers practical advantages in manufacturing and robustness against errors.