Persistent spectral hole burning in Eu^3+-doped aluminosilicate glass at high temperature

Persistent spectral hole burning at temperatures up to 200 K was first time observed in Eu3+-ion-doped aluminosilicate glass. Glass having a composition of 2-wt. % Eu2O3-containing Al2O3⋅9SiO2 was prepared by heating the gel synthesized from metal alkoxides at 900 °C. The persistent spectral holes were burned in the 7F0→5D0 line of the Eu3+ ions by a dye laser with a bandwidth of ∼1 cm-1, of which width and depth were ∼3 cm-1 and ∼10% of the total fluorescence intensity, respectively, at 77 K. It was found that the hole depth decreased with increasing temperature and was erased above 220 K. The local environment of the Eu3+ ions in glass is discussed with regard to the fluorescence line narrowing spectra of the 5D0→7F1 transition.