Spectroscopic properties and Judd-Ofelt analysis of Eu3+ in Y4Al2O9 crystals

Optical absorption, excitation and emission spectra of Eu3+ ions in Y4Al2O9 were investigated. Judd-Ofelt intensity parameters for f-f transitions were derived from the emission spectra and also from the integrated absorption spectra. These parameters were used to calculate the total spontaneous emission probabilities (AR), lifetimes (τR) and branching ratios (βR) for 5D0 excited state of Eu3+. The calculated values of τR and βR are compared with the measured values for 5D0 level. The stimulated emission cross-sections σ were also evaluated for the 5D0 → 7FJ transitions for the first time in this system.