Monitoring Hydrogen Sulfide Using a Quantum Cascade Laser Based Trace Gas Sensing System

We present the detection of hydrogen sulfide (H₂S) in a quantum cascade laser (QCL) based gas sensing system employing direct laser absorption spectroscopy. The sensitivity is obtained to be 3.61×10⁻⁶ cm⁻¹Hz^−1/2 and the H₂S broadening coefficient in N₂ is analyzed by fitting to the plot of the Lorentzian half width at the half maximum as a function of N₂ pressure is 0.1124 ±0.0031 cm⁻¹⋅atm⁻¹. A simulation based on data from the HITRAN database shows broad agreement with the experimentally obtained spectrum.