Abstract

The whispering-gallery-mode (WGM) laser is a type of laser that has an exceptionally narrow linewidth. Noise-immune cavity-enhanced optical heterodyne molecular spectrometry, which is a detection technique with extraordinary properties that benefit from narrow linewidth lasers, has been realized with a WGM laser. By locking to a cavity with a finesse of 55 000, acetylene and carbon dioxide could be simultaneously detected down to an unprecedented noise equivalent absorption per unit length of $6.6\times {10}^{-14}{\mathrm{cm}}^{-1}$ over 150 s, corresponding to 5 ppt of ${\mathrm{C}}_2{\mathrm{H}}_2$.

© 2017 Optical Society of America

Fiber-laser-based noise-immune cavity-enhanced optical heterodyne molecular spectrometry incorporating an optical circulator

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Doppler-broadened mid-infrared noise-immune cavity-enhanced optical heterodyne molecular spectrometry based on an optical parametric oscillator for trace gas detection

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Shot-noise-limited Doppler-broadened noise-immune cavity-enhanced optical heterodyne molecular spectrometry

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Optical feedback noise-immune cavity-enhanced optical heterodyne molecular spectrometry for sub-Doppler-broadened detection of C₂H₂

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Opt. Lett. 49(2) 202-205 (2024)

Doppler-broadened noise-immune cavity-enhanced optical heterodyne molecular spectrometry down to 4  ×  10⁻¹³  cm⁻¹ Hz^−1/2: implementation of a 50,000 finesse cavity

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Opt. Lett. 40(9) 2004-2007 (2015)