Intense visible fluorescence and energy transfer in Dy3+, Tb3+, Sm3+ and Eu3+ doped rare-earth borate glasses

Tb3+/Dy3+ and Eu3+/Sm3+ doped rare-earth borate glasses have been synthesized and characterized. Under UV excitation, Dy3+, Tb3+, Sm3+ and Eu3+ emit intense yellowish white, green, reddish orange and red lights, respectively. In Tb3+/Dy3+ co-doped glasses, the enhancement of Tb3+ green emission is observed, and the sensitization is related to the efficient energy transfer from Dy3+ to Tb3+. In Eu3+/Sm3+ co-doped glasses, the excitation wavelength range of Eu3+ emission is broadened owing to the energy transfer from Sm3+ to Eu3+. This broadening makes the Ar+ 488 nm wavelength laser a powerful excitation source for Eu3+ fluorescence. The rare-earth doped glasses with various visible emissions are useful for developing new color light sources, fluorescent display devices, UV-sensor and tunable visible lasers.