Mechanism of the Three-Photon Population of Ion-Pair States of Iodine via Valence States Near the I2P1/2 + I2P1/2 Dissociation Limit

Abstract

The mechanism proposed in the literature and explaining the population of ion-pair states I₂ (D \(0_{{\text{u}}}^{ + }\)) and I₂ (β 1_g) when a mixture of I₂ vapor and a rare gas is irradiated with the first harmonic of a YAG laser (λ_f = 1064 nm) and the emission of a dye laser tuned to the region of the I₂ (B ← X) transition, is discussed. Alternative mechanisms involving nonlinear optical effects that can occur when iodine vapor is exposed to laser radiation are considered.