Two-photon dual-comb LiDAR imaging

TL;DR

This paper introduces a novel two-photon dual-comb LiDAR technique that uses sub-picosecond laser pulses to achieve centimeter-scale 3D imaging with micrometer precision, surpassing traditional LiDAR accuracy.

Contribution

The work presents a new LiDAR imaging method based on two-photon dual-comb ranging with femtosecond lasers, achieving high accuracy and precision over a stand-off distance.

Findings

Achieved 9-38 μm ranging accuracy at 40 cm distance.

Demonstrated μm-level precision with 500 ms integration.

Successfully imaged an aluminum object and validated with coordinate measurement machine.

Abstract

Conventional LiDAR uses time-of-flight data from laser pulses scanned across a scene to provide accurate multi-meter-scale three-dimensional models at cm precision, limited by the tens-of-picoseconds precision of time-tagging electronics. Here, by using two-photon dual-comb ranging, we introduce an analog of LiDAR imaging using the time-of-flight of sub-picosecond laser pulses to render cm-scale point-cloud datasets with $\mu$m precision. Using only free-running femtosecond lasers, the technique combines absolute accuracy with near-interferometric precision, is applicable to discontinuous surfaces with poor optical quality, and provides a stand-off range exceeding that of other optical metrologies. We demonstrate imaging of an aluminum test object and assess its accuracy by comparing our results with those from a touch-probe coordinate measurement machine. At a stand-off distance of 40 cm, we obtain ranging accuracies of 9 $\mu$m - 38 $\mu$m, and precisions averaging to 1.0 $\mu$m after 500 ms.