Enhanced single-photon time-of-flight 3D ranging

Area of Science:

• Photonics and Imaging Technology
• Computer Vision and Robotics
• Sensor Systems Engineering

Background:

• Traditional 3D imaging systems often face limitations in speed, depth range, and data integration.
• Acquiring high-resolution, depth-resolved information in real-time is crucial for advanced applications.
• Single-photon detection offers enhanced sensitivity and timing precision for depth measurement.

Purpose of the Study:

• To develop a novel system for acquiring 3D depth-resolved maps using Time-of-Flight (TOF) of single photons.
• To demonstrate the system's capability for rapid scanning of large scenes and improved depth information processing.
• To integrate 2D and 3D data for enhanced object recognition and tracking.

Main Methods:

• Utilized a 32x32 CMOS array of Single-Photon Avalanche Diodes (SPADs).
• Integrated 350 ps resolution Time-to-Digital Converters (TDCs) within each pixel for photon timing.
• Developed techniques for TDC unwarping and refolding to enhance signal-to-noise ratio and depth range.

Main Results:

• Achieved acquisition of photon-counting or photon-timing frames every 10 µs.
• Demonstrated scanning of large scenes within hundreds of milliseconds.
• Successfully merged 2D and 3D information into a single image.

Conclusions:

• The developed system enables fast and accurate 3D depth mapping using single-photon TOF.
• Exploitation of TDC features significantly improves signal quality and extends depth measurement capabilities.
• Integrated 2D/3D imaging facilitates improved object recognition and tracking in complex scenes.