Abstract
This paper describes the design and performance of a tunable diode laser system, incorporating a multipass absorption cell to allow determination of water concentration below 10 ppb and carbon dioxide concentration below 1 ppb in nitrogen semiconductor gas. The cell is used with a tunable Pb-salt diode laser spectrometer frequency locked to a first derivative error signal from an intense vibration–rotation molecular absorption line. Sample concentrations are monitored in the second derivative mode, and the system automatically compensates for laser intensity fluctuations. A flowing gas method is used to minimize adsorption/desorption effects from the sample cell walls.
© 1989 Optical Society of America
Full Article | PDF ArticleMore Like This
J. Reid, J. Shewchun, B. K. Garside, and E. A. Ballik
Appl. Opt. 17(2) 300-307 (1978)
Christoph Dyroff, Andreas Zahn, Wolfgang Freude, Bernd Jänker, and Peter Werle
Appl. Opt. 46(19) 4000-4007 (2007)
J. Barry McManus, Paul L. Kebabian, and Charles E. Kolb
Appl. Opt. 28(23) 5016-5023 (1989)