Oxygen Sensor Based on Tunable Diode Laser Absorption Spectroscopy with a Vertical Cavity Surface-Emitting Laser

Abstract

Oxygen plays a fundamental role in nature and industrial process, the fast on-line oxygen concentration detection is of great significance. Tunable diode laser absorption spectroscopy (TDLAS) is capable high selective, high sensitive, non-intrusive, this technique exploits the diode laser tunable and narrow bandwidth characteristics, by selecting one absorption line of the target gas to avoid interference from other gas and realize oxygen concentration fast on-line detection. In this paper, we use vertical cavity surface-emitting laser (VCSEL) as the light source, adopting the wavelength modulation spectroscopy and the harmonic detection technology to measure the second harmonic signal and realize oxygen concentration fast on-line detection. The detection concentration range between 0.1% to 40% and detection accuracy is 0.1%.