Effect of OK bonds on persistent spectral hole burning of Sm2+-doped glasses

Persistent spectral hole burning (PSHB) was investigated in Sm2+-doped Al2O3. 9SiO(2) glass samples with and without OH bonds. The holes were burned in the F-7(0) --> D-5(0) line of the Sm2+ 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 Sm2+ ions, and the holes burned by the rearrangement of the OH bonds were thermally refilled. (C) 1998 Elsevier Science B.V. All rights reserved.