Chinese Optics Letters, Volume. 23, Issue 12, (2025)

Cavity-enhanced absorption spectroscopy with continuous and fast wavelength tuning [Early Posting]

Nie Qinxue, Wang Zhen, Ren Wei
Author Affiliations
  • The Chinese University of Hong Kong
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    We report the development of cavity-enhanced laser absorption spectroscopy with continuous wavelength tuning using a dual-feedback locking scheme. A compact optical cavity of 8 cm is used for achieving an effective optical path of 80 m in a volume of only 10 ml. Compared to the traditional cavity-enhanced absorption spectrometers, our approach sweeps an absorption feature with a full width at half maximum (FWHM) of 420 MHz in 5 seconds, achieving a spectral resolution at MHz-level. We also introduce a novel method to easily and precisely calibrate the frequency tuning range. Our study proves the feasibility of conducting high-sensitivity, high-resolution and rapidly tunable absorption spectroscopy in an optical cavity.

    Paper Information

    Manuscript Accepted: Jul. 10, 2025

    Posted: Jul. 16, 2025

    DOI: 10.3788/COL202523.121201