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Mid-infrared molecular spectroscopy in the quantum noise limit
Published
Author(s)
David A. Long, Adam J. Fleisher, Qingnan Liu, Joseph T. Hodges
Abstract
A cavity ring-down spectrometer was used to reach the quantum noise limit in the mid-infrared spectral region. Quantum noise was observed not only in the individual ring-down decay events but also in the corresponding ensemble statistics with a magnitude which is commensurate with theoretical predictions. With this instrument a noise-equivalent absorption coefficient of 2.6×1011 cm1 Hz1/2 was demonstrated with less than a microwatt of optical power incident of the photodetector. We believe that this spectrometers combination of high sensitivity and robustness make it well suited for measurements of ultra-trace gas species as well as applications in fundamental physics.
Long, D.
, Fleisher, A.
, Liu, Q.
and Hodges, J.
(2016),
Mid-infrared molecular spectroscopy in the quantum noise limit, Physical Review Letters, [online], https://doi.org/10.1364/OL.41.001612
(Accessed October 1, 2025)