Luminescence self-quenching in Tm3+:YLF crystals:: II.: The luminescence decay and macrorates of energy transfer

Microparameters of migration and self-quenching of luminescence from the (P-3(0), I-1(6)) levels of Tm3+ ions are calculated and the luminescence decay from the H-3(4), (1)G(4) and D-1(2) levels are analyzed the concentration series of LiY1-xTmxF4 (x = 0.5 - 10 at. %) crystals upon weak selective excitation. It is shown that the luminescence decay of a thulium ion concentration higher than 0.5 at. % cannot be described by the energy transfer that takes into account only the dipole-dipole interaction. The comparison of experimental kinetic curves with theoretical curves calculated within the framework of the known energy transfer models showed that multipole-multipole interaction is responsible for the self-quenching of the thulium levels. Contributions of higher multipole interactions to the self-quenching are estimated. The decay of luminescence from the 3H4, (1)G(4), and D-1(2) levels of Tm3+:YLF crystals with different concentrations of thulium ions is described analytically. (C) 2001 MAIK "Nauka/Interperiodica".