High-power supersonic CO laser on fundamental and overtone transitions

Lasing parameters of a rf discharge-pumped CO laser in a subsonic gas flow with subsequent cooling of the laser medium in a supersonic flow are studied. The output power of the laser achieved 2.1 kW for the efficiency up to 21 % in the spectral range 4.9 - 5.7 mu m corresponding to the V + I -> V fundamental vibrational transitions in the CO molecule. The laser output power at the V + 2 -> V first vibrational overtone transitions (2.6-2.7 mu m) was 50 W. Possible ways of improving the laser design for generating radiation at higher overtone transitions of the CO molecule are discussed.