Efficient pulsed first-overtone CO laser operating within the spectral range of 2.5-4.2 /spl mu/m

Abstract

Output characteristics of a single-pulse e-beam controlled discharge laser operating on the first-overtone (FO) transitions (/spl Delta//spl nu/=2) of CO molecules 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 /spl mu/m on vibrational transitions from 6/spl rarr/4 up to 37/spl rarr/35. A maximum output efficiency of 11%, the highest ever published for a FO CO laser, has been experimentally obtained for the broad-band multiline FO CO laser. Maximum specific output energy is 50 J/1 Amagat. FO CO lasing was observed within a predischarge gas temperature range 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%. Experiments with a single-pulse FO CO laser using a diffraction grating as a frequency-selective element demonstrated the feasibility of developing a frequency-tunable single-line FO CO laser. Tunable FO CO lasing on wavelengths from 2.7 up to 4.2 /spl mu/m corresponding to vibrational transitions from 13/spl rarr/11 up to 38/spl rarr/ 36 was obtained. The maximum specific output energy came up to 2.8 J/1 Amagat, with single-line output efficiency being up to 0.6%.