Characterisation of QCLs and Development of QCL-Modules for Gas Sensing Applications

摘要

Quantum Cascade Lasers (QCLs) are novel laser sources in the mid infrared spectral region (MIR, 3-30 μm). Using QCLs 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 CO, CO_(2), NO, N_(2)O, and NH_(3) sensitivity limits far below 1 ppm·m are obtained. The method is suitable for open path measurements with simultaneous determination of the actual pathlength as well as for extractive and in-situ measurements.