IEEE Access (Jan 2024)
Simultaneous Enhancement of Viewing Angle and Angular Resolution of Integrated Lidar With Bidirectional Signals and Orthogonal Polarizations
Abstract
Coarse wavelength division multiplexing (CWDM) technology has been widely used in short-reach optical communication systems. By using the same technology in a solid-state photonics-based Lidar, one can achieve significant cost reduction. Beam steering is realized through diffraction of light wave upon grating couplers. However, current design has a small viewing angle and a low angular resolution. We propose a configuration based on Silicon-on-Insulator (SOI) waveguide grating coupler. The viewing angle is increased by 2.5 times with light signals propagating bidirectionally. The angular resolution is doubled through interleaving beams with trans-electrical (TE) polarization and beams with trans-magnetic (TM) polarization. By optimizing the design of a single grating coupler, the output beams are evenly distributed and the transmittance is improved. With 4 CWDM lasers being the source, a 34° beam angle of view and an angular resolution of 1.9° are demonstrated.
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