Detection of HCl on the first and second overtone using semiconductor diode lasers at 1.7 and 1.2 micron

Using a semiconductor diode laser spectrometer, HCl absorption is studied on the first (2nu) and second (3nu) overtones at 1.7 mm and 1.2 micron, respectively. The P(3) component at 1207.91 nm and the R(3) component at 1742.38 nm are investigated at different gas pressures, in order to extract the self-broadening parameters. Sensitivity studies are also performed, to evaluate the minimum detectable concentration of HCl in air