Effects of yttrium codoping on fluorescence lifetimes of Er3+ ions in SiO2–Al2O3 sol–gel glasses

In order to find a new glass host and optimize erbium doping for IR glass optical amplifiers in photonic applications, a study on the optimization of the emission of erbium ions in the SiO2–Al2O3 glass by codoping with Y2O3 is performed. It is first attempted to make a new sol–gel glass host based on SiO2, Al2O3, and Y2O3 doped with Er3+ ions of the composition (1−x)SiO2–xAl2O3–yY2O3:0.65Er2O3 (in mol%), x varies from 0 to 65, and y from 0 to 4. The optimal proportion in mol% of SiO2 and Al2O3 for the Er3+ emission (at a fixed optimal concentration of 0.65) was 65 – 35. The effect of Y2O3 content on photoluminescence, decay curve profiles and lifetime of the 4I13/2 level of Er3+ in SiO2–Al2O3 glass is observed. The largest quantum efficiency and the higher emission intensity are observed in the sample with 65Al2O3 and 4Y2O3. The emission intensity at 1530 nm is two times higher than in glasses without Y2O3. A shift of 3 nm to shorter wavelengths is observed. The emission spectral profiles are flatter and broader for the glasses containing Al and Y (bandwidth of 59.5 nm). The decay curves show strong difference profiles for the different samples. The increase of the lifetime value τ (about ms) of the 4I13/2 level of Er3+ in the SiO2–Al2O3 with the Y2O3 is discussed.