Room temperature persistent spectral hole-burning in sol-gel-derived glasses doped with Eu3+ ions

Persistent spectral hole burning was investigated for the Eu3+ ions-doped glasses prepared by a sol-gel method. For the glasses containing OH bonds, persistent spectral hole is burned by the laser-induced rearrangement of the OH bonds surrounding the Eu3+ ions, which is thermally unstable to erase up to similar to200 K. On the other hand, the Eu3+-doped Al2O3-SiO2 glasses which are heated under H-2 gas or irradiated with X-ray exhibit room temperature PSHB. The depth of the burnt hole increases as the Al2O3 content increases. The hole-formation could be explained by a model of the excitation of the Eu3+ ions and subsequent electron transfer with the excited [Eu3+] or oxygen-defect centers in the Al-O bonds. The burnt holes are more stable compared with those burned by the rearrangement of the OH bonds.