ER-3+ UP-CONVERSION FLUORESCENCE OF MFN-BAF2-YF3-ERF3(M-ZR, HF, AL, GA, IN, SC OR ZN) GLASSES

An effect of the kind of glass-former on the Er3+ upconversion fluorescence in fluoride glasses was examined in the MFn-BaF2-YF3-ErF3 system where MF(n) is ZrF4, HfF4, AIF3, GaF3,InF3,ScF3 or ZnF2. The emission intensities of Er3+ upconversion fluorescence excited by 800 nm radiation from an AlGaAs laser diode varied remarkably with the kind of glass-former. The multiphonon relaxation rates of glasses, which were evaluated from the phonon sidebands of Eu3+, also changed with the kind of glass-former. Contrary to expectation, there was no correlation between the emission intensity and the multiphonon relaxation rate. It was suggested that, in fluoride glasses, a multiphonon relaxation rate is not a main factor determining the emission efficiency of Er3+ upconversion fluorescence.