Sol-Gel Processing of Sm2+-Doped Glass and Its Spectral Hole Burning at Room Temperature

The sol-gel process was applied to the preparation of Sm2+ ion-doped silicate glasses, which show persistent spectral hole burning at room temperature. The gels synthesized by the hydrolysis of metal alkoxides and SmCl3 · 6H2O were heated in air at 500°C, were then reacted with H2 gas to form the Sm2+ ion. The Al2O3-SiO22 glasses are appropriate to reduce the Sm3+ ion with H2 gas and show intense photoluminescence of Sm2+ ion. Persistent spectra hole burning was observed in the excitation spectrum for the 7 F0 → 5D0 transition of the Sm2+ ion by the irradiation of DCM dye laser. The hole width and depth were ∼16 cm-1 and ∼ 10% of the total intensity, respectively, at 20°C.