Dispersion spectroscopic sensing of trace gases, measuring the anomalous dispersion at a molecular resonance rather than absorption, has experienced increased attention in the past view 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 we conclude that dispersion spectroscopy cannot outperform absorption spectroscopy in most experimental situations. In some applications, where the optical power reaching the detector is unstable, dispersion spectroscopic techniques can, however, be advantageous.
Jakob Hayden, Pedro Martín-Mateos, Pablo Acedo, and Bernhard Lendl, "A quantitative comparison of dispersion- and absorption-spectroscopic gas sensing," Proc. SPIE 10110, Photonic Instrumentation Engineering IV, 101100Z (Presented at SPIE OPTO: February 02, 2017; Published: 20 February 2017); https://doi.org/10.1117/12.2252624.
Conference Presentations are recordings of oral presentations given at SPIE conferences and published as part of the conference proceedings. They include the speaker's narration along with a video recording of the presentation slides and animations. Many conference presentations also include full-text papers. Search and browse our growing collection of more than 12,000 conference presentations, including many plenary and keynote presentations.