Oxidation of Sm2+ in β-irradiated Sm-doped borosilicate glasses under laser illumination

Borosilicate glasses doped with samarium have been prepared. Samples exposed to 4×109 Gy of β-irradiation have been investigated by fluorescence measurements, showing a strong reduction process of Sm3+ to Sm2+ ions in the irradiated samples. Oxidation of Sm2+ was observed in this glass as a result of frequency-doubled cw Nd:YAG laser irradiation, but not when using a pulsed titanium-doped sapphire laser. Influence of laser intensity was studied, showing that an increase of the laser intensity could induce complete oxidation of Sm2+ ions. Such effect is not observed at low temperature nor using ultra short laser pulses. The conclusion is that the effect is of thermal origin.