Strategies of precision enhancement for dual-comb time-of-flight distance measurement with nonlinear detection by numerical simulation

High-precision and long-range absolute distance measurement is a vitally important topic in large-scale metrology, and it has broadened applications in the manufacturing industry. Especially, the dual-comb time-of-flight distance measurement is a promising method combining with the advantages of fast speed and high accuracy. The measurand would be determined by asynchronous optical sampling (ASOPS) methods with a slight difference in repetition rates. Here, the home-built optical platform of the Er-fiber femtosecond frequency combs would be introduced with a repetition rate of around 200 MHz and carrier-envelope offset frequency of 20 MHz. Besides, the strategies of precision enhancement for dual-comb time-of-flight distance measurement with nonlinear intensity detection are discussed by the numerical simulation. The sampling interval could be optimized by choosing a proper range of repetition rate and difference of repetition rates. A fine curve fitting method is also proposed for further precision improvement. The results of numerical simulation would provide a valuable reference for the experimental process.