Passive Q-switching of a CO(2) laser by CH(3)F: an analysis

The phenomenon of passive Q-switching of a CO(2) laser by CH(3)F is observed experimentally and analyzed by the use of a set of rate equations which describe the energy transfer processes in the laser-absorber system. The parameters which appear in the laser rate equations are measured in a separate series of measurements under the actual lasing conditions which exist during the Q-switching experiment. The parameters of the absorber rate equations were verified in a separate cw saturation experiment. The result of the Q-switching experiment shows that the present model can give a good account of the dependence of the pulse width, pulse peak power, and the pulse period on the absorber pressure. It is found that cross relaxation in the absorber plays a crucial role in this dependence. Another result of this study is that the integrated intensity of the nu(3) band of CH(3)F is equal to 619 +/- 28 cm(-2) atm(-1) at 300 K.