Measurements of anomalous gain coefficients in transversely excited CO2lasers

We have made a detailed study of the gain coefficients of more than 150 transitions in the [ and [ bands of CO2. Measurements were made in a transversely excited discharge at pressures of 80 and 425 torr. Many lines were found to have anomalously high gain coefficients, but all the anomalies are accurately predicted by a model which takes into account the effect of overlapping transitions. Our results indicate that the majority of transitions in an atmospheric pressure discharge have anamalous gain coefficients under typical discharge conditions. This fact has not been generally recognized, and the neglect of overlapping transitions can lead to errors in determining rotational temperatures.