Optical Ranging Using Coherent Kerr Soliton Dual-Microcombs With Extended Ambiguity Distance

Abstract

Optical ranging is a key technology in metrology. Dual-comb ranging is shown to provide several advantages in light ranging, offering high precision with high acquisition rate. However, performance of traditional dual-comb ranging systems based on microcombs are limited by the short ambiguity distance, requirement of high-bandwidth detectors and complex control loops for stabilization. Here, we show that the compatibility with low-bandwidth detectors of dual-comb ranging system can be achieved by using coherent Kerr soliton microcombs generated by a shared light source, which significantly enhances the coherence without additional control. This approach also significantly reduces the computational cost, providing a route to real-time processing. According to vernier effect, the ambiguity distance is extended to 3.28 m from about 1.5 mm by switching the two combs and the uncertainty reaches about 1.05 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$\times\, 10^{-7}$</tex-math></inline-formula>. Combining coherent microcomb ranging systems with special FPGA could enable comb-based real-time ranging systems for several applications such as industrial process monitoring.