Collisional Effects On Quantum Cascade Laser Induced Molecular Alignment

Intra-pulse quantum cascade laser spectrometers are able to produce both saturation and molecular alignment of a molecular gas. The resultant time domain spectra resemble those seen in coherent optical nutation experiments. In this paper we discuss the ways in which this technique may be used to investigate nitrous oxide-foreign gas collisions, and also those involving a Dicke narrowed line of water. In both cases the chirp rate dependence of the pressure broadening, and its dependence on the collision partner is demonstrated.