| Several optical measurements were used to characterize rare earth doped glasses, with an emphasis on quantum efficiency. Glass hosts included in this study were: silicate, NaZnTeO, PbBiGaO, ZBLAN, GeGaS, GeAsS, GeSI, BaGeGaS and {dollar}rm Assb2Ssb3{dollar} (with and without iodine). Data obtained from optical absorption and fluorescence spectra and fluorescence lifetime measurements were used for theoretical predictions of quantum efficiency. These theoretical efficiencies were compared to absolute measurements of quantum efficiency, using either an integrating sphere based system or a self calibration technique. The latter method could only be used for Pr{dollar}sp{lcub}3+{rcub}{dollar} doped samples. A photon ratio efficiency was found when the quantum efficiency could not be measured directly.; The measured 1.3 {dollar}mu{dollar}m emission quantum efficiency from Pr{dollar}sp{lcub}3+{rcub}{dollar} doped glasses was highest for a 100 ppm {dollar}rm Prsb2Ssb3{dollar} doped GeGaS glass. The Judd-Ofelt predicted 78% was near the 93% found via the integrating sphere, and the 71% found by the self calibration method. The latter technique produced erroneous values for glasses having electronic absorption edges beyond 500 nm, possibly due to a host sensitization phenomenon. While Pr{dollar}sp{lcub}3+{rcub}{dollar} doped {dollar}rm ASsb2Ssb3{dollar} was the worst performing glass of the group, the addition of 1.7 mole% iodine to the composition substantially increased the 1.3 {dollar}mu{dollar}m efficiency. The 1.3 {dollar}mu{dollar}m emission from Dy{dollar}sp{lcub}3+{rcub}{dollar} doped chalcogenide glasses was found to be less efficient than predicted, possibly due to an excited state absorption to higher energy levels.; Pr{dollar}sp{lcub}3+{rcub}{dollar} fluorescence at 1.3 {dollar}mu{dollar}m was sensitized in ZBLAN using Er{dollar}sp{lcub}3+{rcub}{dollar} and {dollar}rm Ersp{lcub}3+{rcub}-Ybsp{lcub}3+{rcub}{dollar} for a pump wavelength of 800 nm. The latter exhibited a photon ratio efficiency of 1%, compared to 0.15% for Er{dollar}sp{lcub}3+{rcub}{dollar} alone and 3.4% for Pr{dollar}sp{lcub}3+{rcub}{dollar} doped ZBLAN pumped at 1017 nm.; Measured quantum efficiencies and photon ratio efficiencies for the 1.3 {dollar}mu{dollar}m emissions from Pr{dollar}sp{lcub}3+{rcub}{dollar} and Dy{dollar}sp{lcub}3+{rcub},{dollar} as well as those emissions from Tm{dollar}sp{lcub}3+{rcub}{dollar} (1.2 {dollar}mu{dollar}m, 1.47 {dollar}mu{dollar}m and 1.8 {dollar}mu{dollar}m), were highest for the chalcogenide glasses. Some radiative transitions (1.3 {dollar}rmmu m-Dysp{lcub}3+{rcub};{dollar} 1.2 {dollar}rmmu m-Tmsp{lcub}3+{rcub}){dollar} could only be detected in chalcogenide glasses. This supports the theoretical findings in this study, as well as other works, that rare earth fluorescence is more efficient from glasses with lower phonon energies. |
