~2 µm Luminescence properties and nonradiative processes of Tm3+ in silicate glass

Two novel Tm3+-doped silicate glasses (one with fluoride addition) with good thermal stability were prepared in this work. Luminescence properties of these two samples were compared. After the addition of fluoride, the luminescence intensity of 1.8 µm was much improved whereas that of 1.47 µm was reduced. The rates of nonradiative processes populating and depopulating 3F4 were calculated quantitatively and a new method of calculating the quenching rate of hydroxyls was proposed. It was found that multiphonon relaxation rate of 3F4→3H6 was really low and could be neglected in both samples. The addition of fluoride in glass could reduce the quenching rate of hydroxyls but raised the cross-relaxation (3H6+3H4→3F4+3F4) rate. Thus the quantum efficiency of 1.8 µm luminescence was improved after the introduction of fluoride.