Carrier-suppressed single-sideband multi-tone coherent LiDAR with long-range field demonstration

This is the authors' abstract. We don't add key points for this paper.

We propose and experimentally demonstrate a carrier-suppressed single-sideband (CS-SSB) phase-based multi-tone coherent LiDAR (PB-MTCW) architecture. In the previously demonstrated double-sideband (DSB) PB-MTCW system, the detected RF tones are susceptible to sideband-interference-induced amplitude fluctuations, while much of the transmitted optical power remains in the unmodulated carrier rather than in the range-bearing tones. By using an IQ modulator to suppress the optical carrier and one modulation sideband, the proposed CS-SSB architecture concentrates optical power into the information-bearing tones and improves measurement stability. In direct comparison with a DSB reference at equal received optical power, it is shown that the CS-SSB system provides an ∼18 dB increase in detected RF tone strength while operating with ∼12 dB lower transmit power. We achieve millimeter-scale ranging precision at below 10 pW received power for static, dynamic, and rotational targets. The system has also been tested in an outdoor testbed that includes 7.36 km of atmospheric propagation and a spool of fiber that increases the total optical path to ∼14.8 km. Across 75 measurements at three different distances, we achieve σ R < 0.7 cm despite ∼30 dB turbulence-induced received-power fluctuations. Overall, these results establish CS-SSB PB-MTCW as a more stable and power-efficient architecture for phase-based multi-tone coherent LiDAR, particularly in long-range and low-received-power operating regimes.