In this letter we present time resolved measurements of the 3.10 eV (4
00 nm) photoluminescence in germainum-doped silica. The 3.10 eV band a
rises from a triplet to singlet transition in a GeO defect. We find th
at the photoluminescence decays with a time constant of around 100 mus
. There is a delay roughly 10 mus in duration between excitation and t
he appearance of maximum photoluminescence intensity. This is evidence
that an additional energy state contributes to the radiative decay of
the triplet state. This state can exist within the same defect or it
can exist in another defect and transfer energy to the GeO.