Persistent spectral hole burning has been observed above 77 K for the <sup>5</sup><i>D</i><sub>0</sub>–<sup>7</sup><i>F</i><sub>0</sub> transition of Eu<sup>3+</sup> in various silicate glasses melted in a nitrogen atmosphere. A striking and novel feature is that the persistent hole can be burned at room temperature. The spectral hole are undiminished in intensity for 2 h in the dark. The formation of a hole with high thermal stability is accomplished only by a change in the melting atmosphere. At 77 K the efficiency of the hole burning is greater for sodium silicate glasses than for sodium aluminosilicate glasses. A possible hole-burning mechanism, i.e., photoinduced reduction of Eu<sup>3+</sup>, is suggested.
© 1998 Optical Society of America
(160.2750) Materials : Glass and other amorphous materials
(160.2900) Materials : Optical storage materials
(160.5690) Materials : Rare-earth-doped materials
(300.6320) Spectroscopy : Spectroscopy, high-resolution
Koji Fujita, Katsuhisa Tanaka, Kazuyuki Hirao, and Naohiro Soga, "High-temperature persistent spectral hole burning of Eu3+ ions in silicate glasses: new room-temperature hole-burning materials," J. Opt. Soc. Am. B 15, 2700-2705 (1998)