Scanning dual-microcomb spectroscopy

Dual-comb spectroscopy (DCS) is a powerful tool in molecular spectroscopy benefiting from the advantages of high resolution and short measurement time. The recently developed soliton microcomb (SMC) can potentially transfer the dual-comb method to an on-chip platform. In this paper, we demonstrate DCS using two frequency scanning SMCs, termed scanning dual-microcomb spectroscopy (SDMCS). The two SMCs are generated by an auxiliary-assisted thermal balance scheme, and the pump laser frequency sweeps over one free spectral range of the microresonator (similar to 49 GHz) using a feedback control system. The proposed SDMCS has a spectral resolution of 12.5 MHz, which is determined by the minimum sweeping step of the pump laser. Using this SDMCS system, we perform three types of gas molecule absorption spectroscopy recognition and gas concentration detection. This study paves the way for integrated DCS with a high signal-to-noise ratio, high spectral resolution, and fast acquisition rate.

Automated summary

This paper introduces the application of dual-comb spectroscopy (DCS) in molecular spectroscopy and the potential use of the recently developed soliton microcomb (SMC) in the dual-comb method. By using frequency scanning SMCs in scanning dual-microcomb spectroscopy (SDMCS), the researchers successfully performed gas molecule absorption spectroscopy recognition and gas concentration detection. The SDMCS system demonstrated high spectral resolution and fast acquisition rate.