Use of intraresonator spectroscopy in studies of changes of level populations during laser pumping of I2 molecules

The intraresonator spectroscopy method was used in an investigation of changes in the number of particles in a cell containing iodine vapor placed inside a dye laser resonator pumped with argon laser radiation (488.0 and 514.5 nm). It was found that when the argon laser power exceeded 0.05 W, there was a sharp reduction in the populations of the rotational sublevels of the ground state with J"= 13 or 15 and ν" = 0. When the duration of illumination with argon laser radiation (λ= 514.5 nm) of the I₂ molecules was sufficiently long, the emission spectrum of the dye laser exhibited an absorption line of atomic iodine (576.4 nm) due to selective predissociation of the ortho-iodine molecules.