No abstract

No abstract

Dual-comb spectroscopy has been an infusive spectroscopic tool for gas detection due to its high resolution, high sensitivity, and fast acquisition speed over a broad spectral range without any mechanical scanning components. However, the complexity and cost of high-performance dual-comb spectroscopy are still high for field-deployed applications. To solve this problem, we propose a simple frequency domain post-processing method by extracting the accurate position of a specific absorption line frame by frame. After aligning real-time spectra and averaging for one second, the absorbance spectrum of H13C14N gas in the near-infrared is obtained over 1.1 THz spectral range. By using this method, the standard deviation of residual error is only ~0.002, showing great agreement with the conventional correction method. In addition, the spectral resolution is improved from 13.4 GHz to 4.3 GHz compared to direct spectrum averaging. Our method does not require a specially designed common-mode suppression comb, rigorous frequency control system, or complicated computational algorithm, providing a cost-effective scheme for field-deployed Doppler-limited spectroscopy applications.

Dual-comb spectroscopy (DCS) is an emerging and promising spectrometric technique with high resolution, high sensitivity, broad spectral range, and fast acquisition speed. For the recovery of the information encoded on comb modes without resolution loss, two continuous wave lasers are commonly utilized as optical intermedia to track the real-time jitter of dual-comb interferograms. This paper presents a simplified error correction method based on single optical intermedium for quasi-free-running fiber DCS. This method combines the strengths of conventional optical referencing and self-referencing error correction. We acquired whole P branch H13C14N transmittance spectra in the near infrared as a demonstration. In contrast to that of conventional dual intermedium error correction, the standard deviation of our method was merely 0.01 over the 4 THz spectral range. Our method provides a balanced and practical postprocessing routine for high-performance mode-resolved DCS applications.