Population inversion of the vibrational levels in CO2lasers

The vibrational level populations in CO2lasers with mixtures of CO2, N2, CO, and He have been calculated using a method developed previously in [1] and [2]. A number of transition probabilities between the vibrational levels due to molecular collisions, the dependences of the population inversion upon various laser parameters (such as the total and partial pressures of the gases, electron density, and tube radius), and the radial profile of the laser gain are calculated in this paper. The calculations show that the CO molecules formed in the discharge play a significant role in the laser. The results given in this paper and in [2] allow us to explain all the main characteristics of both the pumped and the sealed-off CO2lasers.