Scanning dual-microcomb spectroscopy: A new benchmark for precision spectroscopy

The emerging soliton microcombs have the potential for miniaturized dual-comb spectroscopy (DCS) systems. However, the ultra-high repetition rate of a microcomb limits the spectral resolution of the microcomb based DCS system to similar to GHz. Recently, the comb-teeth of a soliton microcomb were swept synchronously over a full free spectral range by way of a feedback mechanism that stabilizes and locks the detuning of the microcomb. Taking advantage of this technology, a high-resolution scanning dual-microcomb spectroscopy (SDMCS) system was developed, and gas components and gas concentration were determined by measuring the absorption spectra of gas mixture.