Investigation of a plasma recombination laser utilizing an He–Ne mixture excited by λ = 10.6 μ laser pulses

An experimental investigation was made of the lasing characteristics of an infrared recombination laser having as its active medium a plasma produced by optical breakdown of an He–Xe gas mixture using pulsed CO₂ laser radiation. Lasing was observed due to four transitions in Xe I (λ = 2.03, 2.65, 3.43, and 3.65 μ) when its concentration in the mixture was between 0.005 and 1.3% and the total pressure was 20–760 Torr. It was found that a population inversion occurred as a result of heating of the gas in the laser radiation absorption wave and subsequent rapid adiabatic cooling of the resultant plasma during expansion. An investigation was made of the dependence of the lasing parameters on the gasdynamic processes.