Fast gas spectroscopy with pulsed quantum cascade lasers for air quality measurement

Quantum Cascade Lasers (QCL) are novel laser sources in the mid infrared (MIR, 3-30 mum) spectral region. Using QCL compact and highly sensitive laser spectroscopy systems without cryogenic cooling are feasible. With pulsed lasers measurement rates in the 10-100 kHz range are possible. For the gases CO2, NO, and NH3 sensitivity limits below 1 ppm . in are obtained. The method is suitable for open path measurements with simultaneous determination of the actual pathlength.