title: Femtosecond pump-probe measurements of non-radiative relaxation in LiAlO(2):V(3+).
abstract: We report on time-resolved studies of non-radiative relaxation of V(3+) ions in LiAlO(2) by means of a two-beam, pump-probe saturation experiment performed with the 150 fs pulsed output of a Ti-sapphire laser. Exciting into the vibronically broadened [Formula: see text] transition at 800 nm, a (3)T(1) relaxation time of 199 ps has been measured at 4 K. This value decreases to 82 ps at room temperature, representing a reduction in the lifetime of a factor of 2.5 due to internal-conversion processes. The relative probabilities for non-radiative, phonon-assisted barrier hopping and quantum mechanical tunnelling through the potential barrier to the (3)A(2) ground state have been obtained using Mott's expression, yielding best-fit parameters of W(0) = (5.2 ± 1) × 10(9) Hz and W(1) = (7.5 ± 1) × 10(10) Hz for a potential barrier of E(nr) = 530 ± 50 cm(-1).
authors.affiliation: Department of Physics and Astronomy, University of Sheffield, Sheffield S3 7RH, UK.
authors.forename: Jon-Paul R
authors.initials: JP
authors.lastname: Wells
authors.forename: Marek
authors.initials: M
authors.lastname: Grinberg
authors.forename: Klaas
authors.initials: K
authors.lastname: Wynne
authors.forename: T P J
authors.initials: TP
authors.lastname: Han