Infared Stimulated Emission of N2O Trapped in Argon Matrices: Comparison with O3 and CO2

• Published in: The journal of physical chemistry. A, Molecules, spectroscopy, kinetics, environment, & general theory Molecules, spectroscopy, kinetics, environment, & general theory, 2000-03, Vol.104 (8), p.1670-1673
• Main Authors: Chabbi, H, Dahoo, P. R, Gauthier-Roy, B, Vasserot, A.-M, Abouaf-Marguin, L
• Format: Article
• Language: English
• ISSN: 1089-5639; 1520-5215
• DOI: 10.1021/jp9936749

N2O molecules dispersed in argon matrices, at a concentration of 1/2000, are excited to their v 3 = 1 vibrational level by a laser pulse at 2218 cm-1. Stimulated emission of the ν3−ν1 transition is observed when the inversion population is large enough, i.e., when the energy absorbed from the laser pulse exceeds a threshold value. From the measured energy threshold, we derive a “loss coefficient” for the cavity-like polycrystalline excited argon sample (a disk about 200 μm thick and 1.5 mm in diameter). Using this loss coefficient, on the basis of molecular spectroscopic parameters, we predict the inversion population threshold for stimulated emission on other N2O transitions, and for other molecules in identical matrices. The prediction is remarkably consistent with our previous observations on O3 and 13CO2 for which the emitting level (v 3 = 2 and v 2 = 3 or 2, respectively) is populated via intramolecular nonradiative transfers.