Dual-comb interchanging absolute distance measurement with non-ambiguity range extension

Abstract

We demonstrate a rapid and high-precision dual-comb ranging method with a significantly extended non-ambiguity range (NAR). By reasonably setting the polarization combining and splitting of two optical combs, we can obtain two sets of interferograms of signal comb and local oscillator comb interchanging simultaneously. This method allows us to extend the NAR to tens to hundreds of kilometers without changing the repetition rate of the signal comb. With this scheme, we demonstrate a dynamic distance measurement when a moving target crosses a measurement dead zone that is 3–4 times the NAR. The standard deviation of the residual distance is 1.48 μm with a 925 μs update rate. This rapid, high-precision, and NAR extension absolute distance measurement scheme will have broad potential in various ranging applications.