Simultaneous multigas detection with cascaded strongly gain coupled DFB laser by dual wavelength operation

Abstract

Simultaneous detection of hydrogen sulphide and carbon dioxide by dual wavelength operation of a cascaded strongly gain coupled distributed feedback (DFB) laser in the 1575 to 1585 nm region is reported for the first time. By precise dual wavelength tuning of the laser diode both gases were detected using wavelength modulation absorption spectroscopy.