@article{oai:nitech.repo.nii.ac.jp:00004753,
 author = {Nogami, Masayuki and Hayakawa, Tomokatsu and Ishikawa, Tomotaka},
 issue = {20},
 journal = {APPLIED PHYSICS LETTERS},
 month = {Nov},
 note = {Persistent spectral hole burning was observed at room temperature in Eu3+-doped Al2O3-SiO2 glass. The glass was obtained by heating in hydrogen gas to reduce some Eu3+ ions to Eu2+ and the spectral hole was burned in the excitation spectrum of the 7F0→5D0 transition of Eu3+. The depth of the hole burned at 200 K was ?7% of the total excitation intensity and independent of temperature up to 350 K. A possible mechanism for hole burning is the electron transfer between the Eu3+ ions and the Al-related defect centers., application/pdf},
 pages = {3072--3074},
 title = {Room-temperature photochemical hole burning in Eu3+ -doped Al2O3-SiO2 glass},
 volume = {75},
 year = {1999}
}