ROLE OF POWER BROADENING IN INFLUENCING MAXIMUM GAIN OF FAR-INFRARED GAIN MATERIAL

Investigation of the small signal gain in methanol vapor at various pu mping power densities showed that power broadening plays an important role in the appearance of a maximum in the gain of far infrared lasers versus pressure of the laser vapor. Consequently the kinetics of the laser cannot be described by a pure rate equation model used many time s (see, for instance [1], [2]). Therefore, the gain is described by a rate equation model phenomenologically modified by including the power broadening [3] automatically containing the influence of the vibratio nal relaxation which is missed in the usual three level density matrix models [4]-[11]. Behavior of the gain of the methanol 119 mum line as a function of the pressure and pumping intensity is investigated expe rimentally and good agreement is found with the expectation of the mod ified rate equation model [3].