Transfer of vibrational energy to electronic excited states and vibration enhanced carbon production in optically excited V−V pumped CO Original Research Article

CO in helium/argon mixtures are vibrationally excited by absorption of CO laser photons in a specially designed flowing gas cell. High vibrational levels (up to ν = 41) become populated by vibration-to-vibration transfer. Vibrational populations of the CO ground state are obtained by fitting the first overtone emission spectra. Transfer of vibrational energy to electronic excited states as well as vibration enhanced carbon production are studied. The CO (A1Π−X 1Σ+) and the CO (b3Σ+−a3Π) emissions have been observed as well as atomic carbon lines. Several systems of C2 have been observed, of which the (d3Πg−a3Πu) Swan system is the most intense. Quenching of high vibrational levels of the CO ground state significantly decreases the emissions from the electronic excited states of CO and C2, indicating that their formation strongly depends on the vibrational excitation in the ground state. Formation mechanisms for these states are investigated.