A Dynamically Evolving Optical Bit Stream from Soliton Rain for Multiplexed and Robust LiDAR with Millimeter Resolution

ABSTRACT The pursuit of high‐resolution and robust light detection and ranging (LiDAR) is often hampered by the inherent limitations of conventional laser sources, which struggle to simultaneously offer fine spatial resolution and strong resilience against interference. We introduce a novel laser source for LiDAR that exploits a complex nonlinear dynamic state, namely soliton rain, to overcome these challenges. Unlike the conventionally recognized periodic nature of a soliton rain, we discover that under a single soliton condensed phase state, it manifests as a pseudo‐random optical bit stream with intriguing dynamic evolution. The optical spectrum confirms its soliton nature with clear Kelly sidebands. The RF spectrum reveals a bandwidth exceeding 37 GHz and an extremely narrow auto‐correlation peak. We harness this unique source with a time‐bandwidth product (TBP) of 12210 to demonstrate a LiDAR system achieving a record 3‐mm spatial resolution. Furthermore, we demonstrate that the pseudo‐random characteristics are preserved even after extracting a specific spectral portion of the soliton rain via fiber Bragg gratings (FBGs), validating the inherent wavelength‐division multiplexing (WDM) capability of our approach. This unique combination of ultra‐high resolution, robustness, and multiplexing scalability positions our soliton rain LiDAR as a foundational technology for next‐generation high‐speed imaging and sensing networks.