Room-temperature persistent spectral hole burning ofEu3+coupling withAl3+in glass

Abstract

Room-temperature persistent spectral hole burning was observed in ${\mathrm{Eu}}^{3+}\ensuremath{-}\mathrm{d}\mathrm{o}\mathrm{p}\mathrm{e}\mathrm{d}$ ${\mathrm{Al}}_{2}{\mathrm{O}}_{3}{\ensuremath{-}\mathrm{S}\mathrm{i}\mathrm{O}}_{2}$ glasses. The sol-gel-derived ${\mathrm{Eu}}^{3+}\ensuremath{-}\mathrm{d}\mathrm{o}\mathrm{p}\mathrm{e}\mathrm{d}$ 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 ${\mathrm{Eu}}^{3+}$ ions were reduced into ${\mathrm{Eu}}^{2+}$ by heating in hydrogen gas. The spectral holes were burned in the excitation spectra of the ${}^{7}{\stackrel{\ensuremath{\rightarrow}}{{F}_{0}}}^{5}{D}_{0}$ transition of ${\mathrm{Eu}}^{3+}.$ The maximum depth of the hole burned at room temperature was found to be $\ensuremath{\sim}10%$ of the total excitation intensity for both the glasses and independent of the treatment conditions of glasses. A proposed model for hole burning is the excitation of the ${\mathrm{Eu}}^{3+}$ 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.