Influence of gaseous impurities in the CO2 lasers cavity

This paper deals with the influence of gaseous impurities on the performances of CO2 lasers. Controlled small amounts of foreign gases are added to the optimized ternary gaz mixture of a CO2 amplifier and the gain is monitored.Anyway, the impurities do not only influence the gain : the discharge stability and the deposits on the cathodes or the mirrors are very much affected.The effects can be very different depending on the kind of the impurity : 1% of one impurity won’t disturb the laser while a few ppm of another one will decrease significantly the gain.One of the main conclusions is that the gases for CO2 lasers require a specific quality.