Abstract

Dual-comb spectroscopy (DCS) has offered new approach for precise molecular spectroscopy. Recently, dual-comb laser attracts a lot of attention as an alternative to the conventional DCS owing to relatively simple architecture. However, most of dual-comb lasers are supposed to be used under free-running operation and their performance might be not suitable for precise spectroscopy. In this work, a new dual-comb laser, which is polarization-multiplex NALM-based mode-locked laser with gain sharing, is developed. The laser cavity has electro-optic phase modulator to control the cavity length, expecting high mutual phase stability in the short-term region as well as in the long-term region. The output spectra from the cavity are well overlapped with f_rep of 59 MHz and Δf_rep of 116 kHz. The stability of Δf_rep under free-running operation is investigated and Allan deviation of 0.025 Hz at 1 s averaging times is obtained.

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