Efficient first-overtone CO laser frequency tuned within the spectral range of 2.5-4.2 um

摘要

Output characteristics of a pulsed e-beam controlled discharge laser operating at the first-overtone (FO) transitions ($Delta@V $EQ 2) of CO molecule have been studied both experimentally and theoretically. Various sets of dielectric mirrors with high reflectivity in the range of the overtone spectrum have been used for the laser resonator. Multiwavelength lasing has been obtained in the wide spectral range of 2.5 - 4.1 $mu@m on vibrational transitions from 6 $YLD 4 up to 37 $YLD 35. Maximum output efficiency 11%, the highest of eve laser, has been experimentally obtained for the broad band multiline FO CO laser. Maximum specific output energy (SOE) is 50 J/I Amagat. FO CO lasing was observed within an initial gas temperature interval of 100 - 220 K. Spectral characteristics of the overtone laser operating on a selected set of vibrational bands have been analyzed theoretically. Theoretical calculations based on the experimental data predict that multiline FO CO laser efficiency can be increased up to 20%. The experiments with pulsed FO CO laser using diffraction grating as a frequency selective element demonstrated a feasibility of a development of frequency tunable single line pulsed FO CO laser. Tunable FO CO lasing on wavelengths from 2.7 up to 4.2 $mu@m corresponding to vibrational transitions from 13 $YLD 11 up to 38 $YLD 36 was obtained. The maximum SOE came up to 2.8 J/I Amagat, single line output efficiency being up to 0.6%.