Multiphoton-Induced Fluorescence and Ionization of B exp 1 sigma exp + Carbon Monoxide

摘要

The B exp 1 sigma exp + state of carbon monoxide was created by a two-photon absorption of 230-nm laser radiation. The B exp 1 sigma exp + state was identified by the positions of the 0-0 absorption band Q-branch and the vibrational bands of B exp 1 sigma exp + implies A exp 1 PI fluorescence occurring in the 525-nm region. Collision-induced b exp 3 sigma exp + implies a exp 3 PI emission in the 350-nm region was also observed. The lifetimes of both the B exp 1 sigma exp + state and the b exp 3 sigma exp + state were measured as well as the self-quenching rate constants and the B exp 1 sigma exp + quenching rate by N sub 2 . In addition to the two-photon-induced fluorescence of B exp 1 sigma exp + carbon monoxide, a three-photon ionization was observed. Laser power-dependence studies indicated that ionization of the B exp 1 sigma exp + state is readily saturated, implying that most B exp 1 sigma exp + state CO is ionized rather than fluorescing. Measurement of the polarization ratio for circularly and linearly polarized excitation of fluorescence and ionization suggests that another three-photon process is occurring and occurs more efficiently for linear polarization. (ERA citation 08:030643)