High-resolution arrayed waveguide grating-assisted passive optical phased array for 2D beam steering

Abstract

Integrated optical phased arrays (OPAs) based on arrayed waveguide gratings (AWGs) enable two-dimensional (2D) beam steering through wavelength tuning. Achieving a high vertical resolution for practical applications remains challenging due to the waveguide phase errors associated with the large AWG required. Here, we present a high-resolution 65-channel AWG-assisted OPA with 5 inputs. Ultra-low loss silicon nitride waveguide technology and transverse magnetic mode operation are employed for waveguide-phase-error mitigation. A vertical resolution of 0.32° using a single input is attained with a beam width of 0.55° × 0.07° and an alias-free horizontal field of view (FOV) of 30°. By utilizing all 5 inputs, the vertical resolution can be enhanced to 0.06°. Real-time 2D beam steering over a 25° × 5° FOV is demonstrated. To our best knowledge, this work demonstrates the highest vertical resolution reported for an AWG-based OPA.