Astrophysics (Index)About

cavity-enhanced absorption spectroscopy

(passing a beam through a gas multiple times to amplify absorption lines)

Cavity-enhanced absorption spectroscopy (CEAS) is absorption spectroscopy (the investigation of a substance by analyzing spectrographic data on electromagnetic radiation passing through it) that boosts its sensitivity by passing the EMR back and forth through the substance (presumably a gas) using an optical cavity of partially-reflective mirrors facing each other. Absorption lines are enlarged as if they passed through a longer path through the material. The technique is suitable for in situ analysis, such as instruments on solar system planetary landers, where the gas to be analyzed can be imported into the spectrometer's cavity.

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