Room-temperature persistent spectral hole burning of Eu3+ coupling with Al3+ in glass -: art. no. 104205

Room-temperature persistent spectral hole burning was observed in Eu3+-doped Al2O3-SiO2 glasses. The sol-gel-derived Eu3+-doped glasses were heated in hydrogen gas and irradiated with x ray, in which the oxygen deficient centers were induced in Al-O bonds and some Eu3+ ions were reduced into Eu2+ by heating in hydrogen gas. The spectral holes were burned in the excitation spectra of the F-7(0)-->D-5(0) transition of Eu3+. The maximum depth of the hole burned at room temperature was found to be similar to 10% of the total excitation intensity for bath the glasses and independent of the treatment conditions of glasses. A proposed model for hole burning is the excitation of the Eu3+ ion and subsequent hole trapping in the oxygen-defect centers in the Al-O bonds. The burnt holes were easily erased by laser irradiation with the energy different from burning one.