Extensive characterization of the optical feedback cavity enhanced absorption spectroscopy (OF-CEAS) technique: ringdown-time calibration of the absorption scale

• Published in: Applied physics. B, Lasers and optics Vol. 91; no. 1; pp. 203 - 211
• Main Authors: Motto-Ros, V., Durand, M., Morville, J.
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer-Verlag 01.04.2008; Springer
• Subjects: Absorption spectroscopy; Applied sciences; Biological and medical applications; Calibration; Dynamic range; Dynamical systems; Engineering; Exact sciences and technology; Fundamental areas of phenomenology (including applications); Global environmental pollution; Holes; Laser spectroscopy; Lasers; Optical Devices; Optical feedback; Optics; Photonics; Physical Chemistry; Physics; Physics and Astronomy; Pollution; Quantum Optics; Spectra; Transimpedance Gain; Measurement Dynamic Range; Extend Cavity Diode Laser; Optical Feedback; Cavity Mode; Optical injection; Absorption spectrometry; Optical feedback; Brewster's angle; Laser spectroscopy; Optical resonator; Calibration; Laser beam applications; Experimental study; Signal to noise ratio
• ISSN: 0946-2171; 1432-0649
• DOI: 10.1007/s00340-008-2950-5

The paper describes in detail an implementation of the highly sensitive optical feedback cavity enhanced absorption spectroscopic (OF-CEAS) technique. A Brewster-angle cavity has been used to enable resonant optical feedback injection. For the first time, an OF-CEAS-adapted processing allowing calibration of the cavity-enhanced spectra in absolute absorption units has been experimentally verified through the combination of ringdown-time and mode-amplitude measurements. The experimental system performance has been evaluated by measuring very weak oxygen B-band transitions near 688 nm. Absorption spectra covering the range of 1.35 cm -1 have been averaged over the 5-s measurement time at the minimum detectable loss of 3×10 -10  /cm within the measurement dynamic range greater than four orders of magnitude. A detailed signal-to-noise ratio analysis estimates the measurement spectral precision as being 3 MHz (short time scale averaging).