Absolute spectral parameters and fluorescence quantum yield in Dy~(3+) doped germanium tellurite glasses

Fluorescence spectra of Dy3+-doped germanium tellurite(NZPGT)glasses have been determined under the pumping of a violet light emitting diode(LED)using an integrating sphere connected to a CCD detector.The spectral power distribution of the sample under the violet LED excitation was derived from the measured spectra,and the radiant flux,luminous flux and quantum yield of the sample were obtained.The total radiant flux and total luminous flux were calculated to be 1 172μW and 0.034lm,respectively.The radiant flux for the four visible emission bands of Dy3+was derived to be 86 !W,which occupied 7.34% of the whole.The total quantum yield for the visible fluorescence of Dy3+was calculated to be 12.38%.The results suggested that the Dy3+-doped NZPGT glasses were efficiently excited by a violet LED and the single doping of Dy3+achieved efficient yellowish-white fluorescence.More than 10% of the fluorescence quantum yield indicates that the glasses have good application prospect,and the absolute spectral parameters provide a valuable reference for further development of rare-earth ions doped solid-state luminescent materials.