VIBRATIONAL STIMULATED-EMISSION OF (CO2)-C-13 IN SOLID ARGON

Laser excitation of the nu(3) (upsilon = 1) level of (CO2)-C-13 in sol id argon is found to induce strong (nu(1) + nu(2), 3 nu(2))-->(nu(1), 2 nu(2)) and (nu(1), 2 nu(2) --> nu(2)) emissions in the 16 mu m spect ral region. Their sharp threshold in function of the laser excitation density is interpreted as the signature of vibrational stimulated emis sion (VSE). Upon site-selective excitation, the VSE exhibits marked di fferences in threshold, temporal behaviour and relative intensities. I ts time dependence gives some insight into the vibrational dynamics of matrix-isolated CO2. In particular, it suggests for the upper levels of VSE transitions a rather long vibrational lifetime in the us range. (C) 1998 Elsevier Science B.V.