Persistent spectral hole burning and local structure of Eu3+ ions doped in BaO-PbO-P2O5 glasses

Persistent spectral hole burning was observed in Eu3+-doped BaO-PbO-P2O5 glasses, and the dependence of hole properties on the glass composition was investigated in relation to the local structure surrounding the Eu3+ ions. The hole was burned on the F-7(0) --> D-5(0) transition of the Eu3+ ions, the depth of which decreased with increasing PbO content, whereas the hole width increased. The hole was burned at 6 K, filled on increase in temperature, and erased above 120 K. Judd-Ofelt parameters and fluorescence line-narrowing spectra indicated that the symmetry of the Eu3+ site increases and the covalency of the Eu-O bond decreases with increasing PbO content.