Pulsed first-overtone CO laser with output efficiency higher than 10%

Output efficiency as high as 11% and specific output energy up to similar t o 50 J/1 Amagat were experimentally obtained for a cryogenically cooled mul tiline pulsed first-overtone (FO) CO laser for the first time. The longest generated wavelength was 4.1 mu m, corresponding to the 37 --> 35 vibration al transition. FO CO lasing was observed within an initial gas temperature interval of 100-220 K. Theoretical calculations based on the experimental d ata predict that the FO CO laser efficiency can be increased up to 20%. Hig h efficiency and high specific output energy obtained in the experiment pla ces the FO CO laser amongst other high-power lasers. (C) 1999 Published by Elsevier Science B.V. All rights reserved.