Switched time delay elements based on AlGaAs/GaAs optical waveguide technology at 1.32µm for optically controlled phased array antennas

Integrated optical time-shift networks consisting of cascaded pairs of 2×2 linear electro-optic (EO) switches and optical delay lines in GaAs waveguides at 1.32 µm are investigated for true-time optical beamforming in phased array antennas. We report new state-of-the-art results in curved waveguide and corner bend insertion loss, and preliminary results from 2-bit time delay generators (TDGs) constructed in the form of GaAs-based photonic integrated circuits (PICs) utilizing these components. To our knowledge, these are the largest GaAs PICs built to date. These results represent significant progress in our longer-term goal of demonstrating a 7-bit TDG with a loss matching monolithic microwave integrated circuit (MMIC) delay line techniques, while providing very wide bandwidth unmatched by MMIC technology.