Ultrafast Parallel LiDAR with Time-encoding and Spectral Scanning: Breaking the Time-of-flight Limit

TL;DR

This paper introduces a novel all-optical time-encoding and spectral scanning method for LiDAR, significantly increasing frame rates and enabling high-speed 3D imaging for autonomous vehicles.

Contribution

It presents a unique combination of fiber-based encoders and wavelength-division multiplexing for parallel detection and spectral scanning, surpassing traditional time-of-flight limits.

Findings

Achieved 4.4-fold speedup in LiDAR frame rate.

Demonstrated effective 75-m detection range.

Enabled ultrafast LiDAR imaging suitable for high-speed vehicles.

Abstract

Light detection and ranging (LiDAR) has been widely used in autonomous driving and large-scale manufacturing. Although state-of-the-art scanning LiDAR can perform long-range three-dimensional imaging, the frame rate is limited by both round-trip delay and the beam steering speed, hindering the development of high-speed autonomous vehicles. For hundred-meter level ranging applications, a several-time speedup is highly desirable. Here, we uniquely combine fiber-based encoders with wavelength-division multiplexing devices to implement all-optical time-encoding on the illumination light. Using this method, parallel detection and fast inertia-free spectral scanning can be achieved simultaneously with single-pixel detection. As a result, the frame rate of a scanning LiDAR can be multiplied with scalability. We demonstrate a 4.4-fold speedup for a maximum 75-m detection range, compared with a time-of-flight-limited laser ranging system. This approach has the potential to improve the velocity of LiDAR-based autonomous vehicles to the regime of hundred kilometers per hour and open up a new paradigm for ultrafast-frame-rate LiDAR imaging.