High efficiency RF excited CO 2 laser

A CO ₂ laser excited by a transverse capacitative RF discharge is reported that generates in 3He:1N ₂:1CO ₂ + 5% Xe at 16 W at a peak efficiency of 20%. From measured discharge parameters and a model of RF capacitative discharges, the internal reduced electric field, E/ N, of the discharge central gain region is calculated for a 3He:1N ₂:1CO ₂ mixture without xenon. The values of E/ N found, which are considerably lower than the average cross electrode reduced field, approach the optimum values for vibrational pumping by electron collision. Under the conditions in the mixture without xenon, where a maximum efficiency of 17.5% was observed, the calculated efficiency maximum was 20.5%.