Vernier optical phased array lidar transceivers

Area of Science:

• Photonics and Optical Engineering
• Lidar Technology
• Integrated Optics

Background:

• Two-dimensional optical phased arrays (OPAs) face limitations due to grating lobes when row spacings exceed half a wavelength.
• These grating lobes restrict the field of view (FOV), introduce signal ambiguity, and decrease optical efficiency, particularly in lidar systems.

Purpose of the Study:

• To introduce and demonstrate a Vernier transceiver scheme for OPAs to mitigate grating lobe issues.
• To enable wider FOVs, reduce signal ambiguity, and improve optical efficiency in 2D beam-steering applications.

Main Methods:

• Implementation of a Vernier transceiver scheme using paired transmit and receive OPAs with mismatched row periodicities.
• Analysis of two grating lobe suppressing beam-steering configurations, including dynamic Vernier alignment for multi-beam or ultra-fast scanning.
• Experimental demonstration using 2D-wavelength-steered serpentine OPAs.

Main Results:

• Achieved significant grating lobe suppression of 6.4 dB.
• Demonstrated beam steering across a 5.5° range.
• Successfully eliminated return signal ambiguity by aligning only a single pair of transmit and receive lobes.

Conclusions:

• The Vernier transceiver scheme effectively suppresses grating lobes in 2D OPAs.
• This approach enables larger FOVs and reduced complexity in photonic lidar systems.
• Paves the way for advanced 2D beam-steering designs with improved performance.