Nonlinear absorption and spectral conversion of laser radiation by carbon monoxide molecules excited in an electron-beam-controlled discharge

Experimental observations were made of nonlinear absorption of radiation from an electron-beam- controlled CO laser by carbon monoxide molecules that exhibit an initial vibrational nonequilibrium at room temperature in a range of transitions in resonance with the CO laser radiation. It was found that this absorption resulted in optical pumping of high vibrational levels of the CO molecules and in the establishment of a population inversion. A gain of ~1 m^–1 was achieved by combined (optical + electron-beam-controlled discharge) pumping of the active mixture using various vibrational-rotational transitions. Under these conditions, lasing was achieved with a specific output energy of ~5 J·liter^–1·atm^–1.