Ozone-stimulated emission due to atomic oxygen population inversions in an argon microwave plasma torch

摘要

pressure, quasi-resonant energy transfer from metastable argon atoms to molecules of oxygen and ozone generated in the torch shell and, then, to oxygen atoms produced via the dissociation of molecular oxygen and ozone leads to the inverse population of metastable levels of atomic oxygen. As a result, the excited atomic oxygen with population inversions becomes a gain medium for lasing at wavelengths of 844.6 and 777.3 nm (the 3(3)P-3(3)S and 3(5)P-3(5)S transitions). It is shown that an increase in the ozone density is accompanied by an increase in both the lasing efficiency at these wavelength and the emission intensity of the plasma-forming argon at a wavelength of 811.15 nm (the (2)P(0)4S-(2)P(0)4p transition). When the torch operates unstably, the production of singlet oxygen suppresses ozone generation; as a result, the lasing effect at these wavelengths disappears.