Abstract
Using wavelength-modulation spectroscopy and harmonic detection, we demonstrate, for the first time, direct optical detection of H 2 S by probing the v 1 + v 2 + v 3 combination absorption band centred at a wavelength λ = 1.59 μm using a distributed feedback (DFB) laser diode. A detection limit of less than 10 ppm at atmospheric pressure over a 5 m path length for the system is inferred from the measured detectivity at higher H 2 S concentrations. This detection sensitivity is at a level below the accepted 10 ppm safe-exposure limit. In addition, we demonstrate the capability of DFB laser diodes for multiple gas sensing in the λ = 1.575 μm region with the same laser by probing the 2v 1 + 2v 2 + v 3 absorption band of CO 2 , achieving a detection limit of about 100 ppm. These results demonstrate the utility of near-infrared laser diodes for industrial applications in the area of toxic- and trace-gas monitoring.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
