Precise and Fast LIDAR via Electrical Asynchronous Sampling Based on a Single Femtosecond Laser

TL;DR

This paper introduces a novel LiDAR technique using asynchronous electrical sampling of a femtosecond laser, achieving micrometer precision and megahertz update rates for real-time 3D sensing and vital sign detection.

Contribution

It presents a new optical-frequency-comb based LiDAR method that overcomes traditional sampling limitations, enabling high-precision, high-speed environmental 3D measurements.

Findings

Achieved 38.8 μm Allan deviation at 1 MHz update rate.

Achieved 8.06 μm Allan deviation after 2 ms averaging.

Enabled contactless vital sign detection and high-speed 3D imaging.

Abstract

Using a laser-based ranging method for precise environmental 3D sensing, LiDAR has numerous applications in science and industry. However, conventional LiDAR face challenges in simultaneously achieving high ranging precision and fast measurement rates, which limits their applicability in more precise fields, such as aerospace, smart healthcare and beyond. By employing an asynchronous electrical pulse sampling strategy on a single optical frequency comb with a stable repetition rate and femtosecond-pulse width, we exploit the advantages of optical-frequency-comb ranging method and overcome the limitations of sampling aliasing and low data-utilization inherent in traditional approaches. This enables a significant improvement of LiDAR's performance to achieve micrometer-level precision and megahertz-regimes update rates over meter-range on non-cooperative targets. Specifically, we achieve 38.8-${\mu}$m Allan deviation at 1-MHz update rate and 8.06-${\mu}$m Allan deviation after 2-ms time-averaging based on a 56.091-MHz femtosecond laser. This enhancement enables various advanced measurement applications, including metrology monitoring on high-speed objects, 1-megapixel/s precise 3D scanning imaging and first-ever contactless vital sign detection using time-of-flight LiDAR. This LiDAR unlock new possibilities for precise and fast real-time measurements in diverse fields.