Infrared femtosecond laser pulse–induced permanent reduction of Eu^3+ to Eu^2+ in a fluorozirconate glass

作者：Jianrong Qiu, Keisuke Kojima, Kiyotaka Miura, Tsuneo Mitsuyu, Kimihiko Hirao · 发表于：Optics Letters · 年份：1999 · DOI：10.1364/ol.24.000786 · 被引用次数：96 · 研究领域：Laser Material Processing Techniques、Solid State Laser Technologies、Photorefractive and Nonlinear Optics

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.