Room temperature persistent spectra hole burning in Sm2+‐doped silicate glasses prepared by the sol‐gel process

Persistent spectra hole burning is observed at room temperature in the excitation spectrum for the 7F0→5D0 transition of the Sm2+ ions that are doped in aluminosilicate glass. Glass having the composition of Sm2+‐doped Al2O3⋅9SiO2 has been prepared by the sol‐gel processing of metal alkoxides and the reaction with H2 gas at 800 °C. Sol‐gel derived glass enables Sm to be doped in the Sm2+ state of which the 4f6 (7F0)→4f55d band does not overlap with the 5D0→7F0 line. The hole width and depth, which are burned by the DCM dye laser, are ∼15 cm−1 and ∼10% of the total intensity, respectively, at 20 °C.