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arXiv · 2401.14529

Dual-comb spectroscopy using free-running mechanical sharing dual-comb fiber lasers

Haochen Tian·Runmin Li·Takeru Endo·Takashi Kato·Akifumi Asahara·Lukasz A. Sterczewski·Kaoru Minoshima
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Abstract

We demonstrate balanced-detection dual-comb spectroscopy (DCS) using two free-running mechanical sharing dual-comb fiber lasers assisted by an all-computational digital phase correction algorithm. The mutual coherence between the combs allows us perform mode-resolved spectroscopy of gaseous hydrogen cyanide by digitally compensating residual timing and offset frequency fluctuations of the dual-comb signal. Setting the repetition rate difference between the combs to 500 Hz (1.5 kHz) yields more than 2000 resolved radio frequency comb lines after phase correction in a 3-dB bandwidth centered at 1560 nm of wavelength. Through coadding the corrected interferograms (IGMs), we obtain a single time-domain trace with a SNR of 6378 (13960) and 12.64 (13.77) bits of dynamic range in 1 second of averaging. The spectral SNR of the coadded trace reaches 529 (585), corresponding to a figure of merit of SNR of 1.3$\times$10$^6$ (1.4$\times$10$^6$). The measured absorption spectrum of hydrogen cyanide agrees well with the HITRAN database.

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Haochen Tian, Runmin Li, Takeru Endo, Takashi Kato, Akifumi Asahara, Lukasz A. Sterczewski, Kaoru Minoshima. 2024-01-25. Dual-comb spectroscopy using free-running mechanical sharing dual-comb fiber lasers. https://doi.org/10.1063/5.0125689

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