Permanent photoreduction of Sm3+ to Sm2+ inside a sodium aluminoborate glass by an infrared femtosecond pulsed laser

Abstract

We report the observation of permanent photoreduction of Sm3+ to Sm2+ inside a transparent and colorless Sm3+-doped sodium aluminoborate glass. After irradiation by an 800 nm focused femtosecond pulsed laser, the focused part of the laser in the glass became orange. Absorption and photoluminescence spectra showed that a part of Sm3+ was reduced to Sm2+ after the laser irradiation. Electron spin resonance spectra of the glass before and after the laser irradiation were also measured. The observed phenomenon is inferred to be useful for the fabrication of optical memory devices with an ultrahigh storage density.

Three-Dimensional Micro- and Nano-Fabrication in Transparent Materials by Femtosecond Laser

“…We have also observed spaceselective permanent photoreduction of Sm 3þ to Sm 2þ in various glasses and crystals by femtosecond laser irradiation and demonstrated 3D optical data storage by using the femtosecond-laser-induced valence-state change of Sm ions in glasses. [44][45][46] Based on the above results, the present technique will be useful in the fabrication of 3D optical memory devices with high storage density. Optical memory using a valence-state change of rare-earth ions at a spot allow data to be read out in the form of luminescence, thus providing the advantage of a high signal-to-noise ratio.…”

Long-lasting phosphorescence in Mn2+:Zn2GeO4crystallites precipitated in transparent GeO2–B2O3–ZnO glass-ceramics

“…In general, such point defects result in undesirable degradation of electrical and/or optical properties, but they can also be used to exhibit some specific features or applications. A variety of metastable defects in glasses have been observed under an excimer laser and a femtosecond laser induces a variety of metastable defects [1][2][3]. It is hence likely that some novel optical functions can be elicited if the characteristics and quantities of the defects can be controlled.…”

Realization of novel optical functions by controlling glass microstructures

“…[6]. In the transient time phonon vibration is thermally activated, whereas in thermal balance in the steady state, thus the emission at 875 nm is intense in the TR emission spectra and could hardly be observed in the steady-state emission spectrum.…”