Down- and up-conversion of femtosecond light pulse excitation into visible luminescence in cerium-doped Lu(2)SiO(5)-Gd(2)SiO(5) solid solution crystals co-doped with Sm(3+) or Dy(3+).

Abstract

Luminescence phenomena following femtosecond pulse excitation in UV and IR of Ce(3+) + Sm(3+) and Ce(3+) + Dy(3+) systems in Lu(2)SiO(5) - Gd(2)SiO(5) single crystals are investigated. Effect of excitation wavelength in the UV on Ce(3+) luminescence is interpreted assuming selective excitation of weakly interacting Ce1 and Ce2 sites. IR-excited up-converted spectra differ as compared to UV-excited spectra in that the contribution of Sm(3+) or Dy(3+) luminescence is higher and the Ce(3+) luminescence originates essentially in Ce1 sites. It has been concluded that excitation mechanism of up-conversion involves energy transfer from free electrons created in conduction band of the host.