Jinsheng Liao

Radiative-trapping and fluorescence-concentration quenching effects of Yb:YAl 3 (BO 3 ) 4 crystals

The effects of radiative-trapping and fluorescence-concentration quenching on the emission spectra and fluorescence lifetimes of Yb3+-doped YAl3(BO3)4 crystals with a series of Yb3+ concentrations were studied. The shift of barycenters in emission spectra, Δλ, was proposed as an appraisement of the radiative-trapping effect on the spectra, and an empirical relation between Δλ and Yb3+ concentration in the Yb:YAl3(BO3)4 crystals was deduced. The model of excitation random walk was used to analyze the effects of radiative trapping and concentration quenching on the fluorescence lifetimes. The relation between fluorescence lifetime and Yb3+ concentration was obtained.

Polarized spectral properties of Yb3+: Li2Gd4(MoO4)(7) crystal: a candidate for tunable and ultrashort pulse lasers

Detailed polarized spectral properties of a 3.2 at.% Yb3+ : Li2Gd4(MoO4)(7) crystal, including absorption cross-section, emission cross-section, up-conversion spectrum and intrinsic fluorescence lifetime, were investigated. The laser potentiality was also evaluated and the results show that this crystal is a good candidate for tunable and ultrashort pulse lasers.