Luminescence decay kinetics of Ge related center in silica

Detailed measurements of luminescence decay kinetics in Ge doped silica fib er have been carried out for different excitation energies From 3 to 7.7 eV and luminescence detection energy from 2 to 4 eV. The decay kinetics of lu minescence is rather well approximated by an exponent. A distribution of ti me constants over the range 90-130 mu s in decay exponential approximation is pointed out. This distribution is due to structural non-equivalency of G e centers in the disordered glass structure. At 10 K the life time increase s up to 150-450 mu s, and it is explained as influence of zero-field splitt ing of the triplet state. The spectra of luminescence and its excitation al so are affected by inhomogeneous broadening. The excitation with photons ab ove 6.4 eV causes appearance of thermally stimulated luminescence also.