Simplified phase-stable dual-comb interferometer for short dynamic range distance measurement

A simplified phase-stable dual-comb interferometer for absolute distance measurement within a short dynamic range is proposed in this paper. The experimental results demonstrate that stable phase-difference information and lower timing jitter can be obtained within a time delay of 2000 ns between the reference interference signal and measurement interference signal. Using the proposed technique, the time-of-flight (TOF) result can link directly to the carrier-wave interferometric (CWI) result in an average time of 20 ms and can reach 2 nm precision in 0.5 s averaging time. Millimeter-scale measurement dynamic range and nanometer-level precision can thus be achieved without additional noise suppression. This method can also be applied at different stand-off distances.