Theoretical and experimental studies of optically pumped molecular gas lasers

Optically pumped molecular gas lasers based on vibrational-rotational transitions in the infrared spectral region were studied experimentally and theoretically. A model was developed to predict the performance of such lasers and explore their potentials for energy and power scaling. This rate equation model was applied to explore the performance of a second-overtone (pulsed) and a first-overtone (CW) pumped HBr laser. Experimental improvements concerning temperature spectral tuning and frequency stabilization of a Nd:YAG laser that pumped HBr were accomplished. Lasing at 4 microns was demonstrated from such a system. We identified acetylene and hydrogen cyanide as potential laser gases that can be pumped with lasers emitting in the attractive telecommunication C band region at about 1.5 microns. Estimations and fluorescence measurements suggest the possibility of lasing in the 3 micron region. Lasing was demonstrated for the first time with a 5 ns pump pulse from an optical parametric oscillator using traditional cavities. The first gas filled hollow fiber laser based on population inversion was demonstrated with acetylene and emission in the 3 micron region was observed. An analytical model indicates the possibility of CW lasing with small Stokes shift in both acetylene and HCN.Optical science and engineeringDoctoralUniversity of New Mexico. Dept. of Physics & AstronomyWolfgang, RudolphMansoor, Sheik-BahaeSanjay, KrishnaPaul, Schwoebe