[Zurück]

J. Hayden, P. Martin-Mateos, P. Acedo, B. Lendl:
"A quantitative comparison of dispersion- and absorption-spectroscopic gas sensing";
Vortrag: Photonics West 2017, San Francisco; 28.01.2017 - 02.02.2017; in: "Proceedings Volume 10110, Photonic Instrumentation Engineering IV", Proceedings of SPIE, Photonic Instrumentation Engineering IV, Vol. 10110 (2017), S. 101100Z-1 - 101100Z-7.

Dispersion spectroscopic sensing of trace gases, measuring the anomalous dispersion at a molecular resonance rather
than absorption, has experienced increased attention in the past few years. Their advantages over absorption based
spectroscopic sensing are the independence of signals from laser power and their linearity with concentration, even for
optically thick samples. In this contribution, we give a comparative discussion of performance, noise and limitations of
dispersion and absorption spectroscopy. We relate dispersion spectroscopy to phase-shift rangefinding, for which figures
of merit are available in literature. Based on our analysis and the current limitations discussed in the manuscript we
conclude that, in terms of limits of detection, dispersion spectroscopy compares with absorption spectroscopy in most
experimental situations, but is unlikely to outperform it. However, other unique features of dispersion spectroscopy,
thereof especially the linearity with concentration and the independence of power reaching the detector, are highly
beneficial for many applications.

http://dx.doi.org/10.1117/12.2252624