A parametric study of the output of the optically pumped continuous wave CF4 laser

A parametric study of laser output versus CF₄ pressure and temperature was performed and correlated with a model for the gain in the system, which includes the relevant relaxation processes. Lasing in CF₄ was observed at temperatures below 170 K. Cooling the CF₄ gas, the output power of the laser increased from 3 mW at 142 K to 5 mW at 113 K, when 4% of the radiation was coupled out. Chopping the pump, the 16-μm signal consisted of a peak decaying in approximately 2 ms, superimposed on a CW background. This decay is caused by the slow relaxation in the CF₄ laser, resulting in filling of the lower laser level. For the CW CF₄ laser, vibrational relaxation from the laser lower level is even slower than diffusion to the cold cell walls. To increase the relaxation rate, HD was added. In this molecule, the J=1→3 rotational transition at 447 cm^-1 is almost resonant with the ν₂ vibration in CF₄. Maximum CW output was increased by 25% in a mixture containing 10% HD. At the same time, the lasing pressure range was extended