title: Infrared femtosecond laser pulse induced permanent reduction of Eu3+ to Eu2+ in a fluorozirconate glass.
abstract: We report what is believed to be the first observation of permanent photoreduction of Eu(3+) to Eu(2+) in transparent and colorless Eu(3+) -doped fluorozirconate glass at room temperature, using an infrared femtosecond laser. Difference absorption and electron-spin-resonance spectra of the glass before and after laser irradiation showed that a portion of the Eu(3+) ions in the focused part of the laser inside the glass were reduced to Eu(2+) ions after laser irradiation. It is suggested that Eu(3+) ions act as electron-trapping centers, whereas active sites in the glass matrix act as hole-trapping centers, leading to the formation of Eu(2+) ions. The observed phenomenon is inferred to be useful in the fabrication of optical memory devices with high storage density and waveguide-type micro-optical devices.
authors: Hirao Active Glass Project, Exploratory Research for Advanced Technology, Japan Science and Technology Corporation, Keihanna Plaza, Seika-cho, Kyoto 619-0237, Japan.
authors: J
authors: J
authors: Qiu
authors: K
authors: K
authors: Kojima
authors: K
authors: K
authors: Miura
authors: T
authors: T
authors: Mitsuyu
authors: K
authors: K
authors: Hirao