Rapid and High-Precise Ranging With a Frequency-Locked and Coherent Dual-Microcomb Source

High repetition rate dual-microcomb interferometry offers high-precision and fast acquisition, showing broad application prospects in rapid and precise ranging scenarios. In this study, a continuous-wave laser was coupled into two chip-based integrated silicon nitride microresonators to drive two dissipative Kerr soliton optical frequency combs. Their repetition rates, 24.96202 GHz and 24.96121 GHz, were locked to external reference RF sources. Using this dual-microcomb source, we conducted linear displacement experiments within a range of 150 millimeters, with residual errors less than 10 micrometers compared to a reference laser interferometer. In static measurements, the Allan deviation reached 1.6 nanometers at an averaging time of 40 milliseconds. Additionally, with an update rate exceeding 800 kHz, dynamic measurement capabilities were demonstrated by measuring the rapid rotating chopper. To the best of our knowledge, this study is the first to utilize a repetition-frequency-locked coherent dual-microcomb source for ranging experiments, significantly enhancing distance measurement accuracy to the nanometer level compared to free-running systems. The proposed system is of importance for future high-precision LiDAR and remote sensing applications based on dual microcombs, and holds potential in areas such as multi-satellite formation flying and microelectronic device manufacturing.