Effect of OH bonds on persistent spectral hole burning of Sm 2+-doped glasses

Abstract

Persistent spectral hole burning (PSHB) was investigated in Sm 2+-doped Al 2O 3·9SiO 2 glass samples with and without OH bonds. The holes were burned in the 7F 0 → 5D 0 line of the Sm 2+ ions using a Q-switched Nd:YAG laser-pumped dye laser at 77 K. Holes with the depth of about 40% were burned in the samples containing OH bonds, which decreased with increasing time and temperature and reached the depth of one-third of the initial one. On the other hand, the glass containing no OH bonds had a hole depth of about 15%, which was not erased after heating to room temperature. We conclude that the PSHB was formed by both the photo-induced rearrangement of the OH bonds and the photoionization of Sm 2+ ions, and the holes burned by the rearrangement of the OH bonds were thermally refilled.