Mid-infrared molecular spectroscopy in the quantum noise limit
David A. Long, Adam J. Fleisher, Qingnan Liu, Joseph T. Hodges
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.
, Fleisher, A.
, Liu, Q.
and Hodges, J.
Mid-infrared molecular spectroscopy in the quantum noise limit, Physical Review Letters, [online], https://doi.org/10.1364/OL.41.001612
(Accessed December 10, 2023)