High-temperature persistent spectral hole burning of Eu^3+ ions in silicate glasses: new room-temperature hole-burning materials

Persistent spectral hole burning has been observed above 77 K for the 5D0–7F0 transition of Eu3+ 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 Eu3+, is suggested.