Effective multiline pulsed first-overtone CO laser operating in a spectral range of 2.5 to 4.1 μm

Abstract

Output characteristics of a pulsed e-beam controlled discharge laser operating on the first-overtone (FO) transitions (?V=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 µm on vibrational transitions from 6?4 up to 37?35. Maximum output efficiency as high as 11% has been experimentally obtained for the broad band FO CO laser. Output efficiency of the laser operating on a few vibrational bands within the relatively narrow spectral range 2.5-2.7 µm comes up to 5% at entirely suppressed fundamental band (?V=1) lasing. 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%.