The effect of dual-comb system locking scheme on phase noise and spectral resolution

With the advantages of high resolution, high sensitivity, wide spectral coverage and rapid measurement, the dual-comb spectroscopy technology has developed rapidly in the field of molecular and atomic spectroscopy. This article firstly uses various methods such as balanced optical cross-correlation method and beat frequency with ultra-stable laser to measure the phase noise of the dual optical comb system for different optical comb locking schemes. Then the absorption spectra of C2H2 were measured for the dual comb system under different locking schemes. The phase noise obtained under different locking schemes is compared, and the C2H2 absorption spectrum under each scheme is calculated at the same time, so as to obtain the influence of phase noise on the spectral resolution in the dual-comb spectrum measurement.