The kinetics of the luminescence decay in the bands 488, 543
and 584 nm, as shown in Fig. 5 b–d, are close to the exponential
one. The deviation from the exponential dependence in the range
of ?1–1.5 ms is observed for the transitions from the excited
5 D 4
level in the terbium ion to the ground state in all the cases at the
initial stage.