Power enhancement of the cw 12.08 μm NH3 Raman laser with the addition of H2/He buffer gases

The effects of H₂, He, and N₂ buffer gases on the efficiency of the cw 12.08 μm NH₃ Raman laser are studied experimentally. The laser output power is increased by nearly 60% with the addition of H₂ or He, which we essentially attribute to the high thermal conductivity of these buffer gases. In the optimum conditions (NH₃/H₂:1/1 mixture with 0.35 Torr partial pressure of NH₃) 3.3 W output power at 12.08 μm is obtained which corresponds to 11% power conversion efficiency.