Infrared pulse transmission in SF6-He mixtures

The transmission of
Q
-switched CO
2
laser pulses through SF
6
-He mixtures is studied experimentally and compared with predictions generated by computer calculations based on a four-state model for SF
6
. The results show that for saturating fields the factor determining the rate of absorption is the rotational energy transfer process that feeds the levels interacting with the laser. This conclusion has implications for models of passive
Q
switching in molecular lasers and infrared-infrared double resonance.