A free-running dual-comb spectrometer with intelligent temporal alignment algorithm

Abstract Dual-comb spectrometer is demonstrated as a promising tool in atmospheric composition detection with extremely-high spectral resolution and fast scanning capability. In this paper, an intelligent temporal alignment (ITA) algorithm is proposed into signal processing of a free-running dual-comb spectrometer around 1.5 μm. The signal processing in the algorithm only relies on the original interference sequence to complete the signal alignment without reference signal. As a result, the alignment of 12CO gas absorption line in the wavelength range of 1564-1570 nm is well retrieved in good agreement with HITRAN database. To the best of our knowledge, this paper proposes and implements for the first time the combination of the ITA algorithm and free-running dual-comb spectroscopy. It lays a technical foundation for the intelligent analysis of arbitrary gas absorption spectral lines.