Self-Correction in Free-Running Dual-Comb Spectroscopy With Varying Interferogram Refresh Rates

The dual-comb spectrometer has emerged as a preferred instrument in multiheterodyne spectroscopy due to its high-resolution and fast-scanning capabilities. Conventional dual-comb spectroscopy (DCS) requires locking or reference systems, increasing both system complexity and cost, and limiting its commercial feasibility. Self-correction offers a promising alternative, though it demands a high refresh rate for interferograms (IGMs), corresponding to the repetition frequency difference, to counter system noise. This study examined the practical effects of self-correction at various refresh rates by measuring $\rm H<^>{13}C<^>{14}N$ absorption. The results indicate that higher repetition frequency differences improve self-correction performance, while lower repetition frequencies cause deviations in absorption line width and intensity. Practical applications must balance measurement bandwidth, which is constrained by the repetition frequency difference.