Experimental realization and characterization of a two–color dual–comb system for practical large–scale absolute distance measurements

•A two-color dual-comb system is realized for the large-scale distance measurement.•The optical properties of the dual-comb sources are investigated by experiments.•The single-longitudinal-mode frequency is evaluated by a commercial comb.•A preliminary ASOPS is demonstrated for a short absolute distance.•A resampling Hilbert transformation for envelope extraction is proposed. In this paper, a two–color dual–comb system has been realized and characterized for the specific applications of the practical large–scale absolute distance measurements, especially for the investigations of asynchronous optical sampling (ASOPS) with a slight difference of repetition rates. The fundamental 1550 nm wavelength is emitting from the Er–fiber femtosecond frequency combs with a repetition rate of around 200 MHz and carrier-envelope offset frequency of 20 MHz, and the other wavelength of 775 nm is generated by the second harmonic generation crystals. The optical characteristics are investigated in detail, and the stability of frequency parameters are also evaluated for long–term time. The preliminary experimental results of ASOPS show that this two-color dual-comb system has the potential to be applied for further diversified research.