Experimental Determination of Laser Level Populations. Vibrational Temperatures

Abstract

The results of calculations (carried out in the preceding chapter) of the population inversion are in satisfactory agreement with the experimental results deduced from measurements of the laser gain [92, 97]. However, it is clear from Eqs. (2.9) and (2.10) that the direct results of such calculations are the vibrational temperatures of molecules in different normal modes and of the absolute populations of the corresponding vibrational levels. The population inversion is then calculated as the difference between the populations of the upper and lower laser levels. Therefore, in a more detailed check of the population inversion mechanisms predicted theoretically it would be desirable to use experimental data on the populations of individual vibrational levels.