Infrared Spectroscopy of Atmospherical and Astrophysical relevant Molecules: Spectral analysis, Line parameter retrievals and Study of collisional decay processes

Abstract

This thesis encompasses different topics in the research field of IR spectroscopy, which includes line-by-line parameter and absorption cross sections retrievals, medium and high resolution analysis, and investigations about collisional processes. The research involving the line-by-line analysis has led to the development of a line-fitting software, VLSFP. Then, the line parameters of SO2 and H2C=CHF has been determined in the 8 – 9 mm atmospheric window by TDL spectroscopy. At medium resolution, the FT-IR spectrum of H2C=CHF has been investigated experimentally and through CCSD(T) ab-initio calculations. At high resolution, the spectrum of CF3Br, has been analysed in the 2v50 and v2 + v3 band regions. Absorption cross sections have been measured for SO2, H2C=CHF and CF3Br. Finally, the physics of the interactions of chirped IR laser radiation with low pressure gases, H2O, N2O and CO2, have been investigated by the frequency down-chirped radiation emitted by a QCL spectrometer employed in the intra-pulse method.