Pulsed laser operating on the first overtone of the CO molecule in the 2.5-4.2-μm range. II. Frequency-selective lasing

Lasing properties of a pulsed electroionisation CO laser operating on the first overtone of the CO molecule in the frequency-selective regime were studied experimentally and theoretically. Lasing was observed on a large number of separate vibrational-rotational transitions ν+2→ν from 13→11 to 38→36 (more than 400 spectral lines) in the spectral range from 2.7 to 4.2 μm. The specific output energy of the overtone CO laser reached ∼3.0 J l-1 amagat-1, and the electrooptical conversion was ∼0.6 %. The formation of emission spectra from high vibrational levels in the overtone CO laser observed for the first time is discussed. The comparison of experimental and theoretical data showed the necessity of including the multiquantum exchange on high vibrational levels into the kinetic model of the active medium of the CO laser. (lasers)