Femtosecond laser-induced long-lasting phosphorescence in Pr~(3+)-doped ZnO-B_2O_3-SiO_2 glass

摘要

This paper studies the phenomenon of long-lasting phosphorescence induced by a femtosecond laser in Pr~(3+)-doped ZnO-B_2O_3-SiO_2 glass. With the glass irradiated by a focused femtosecond laser for a short time, the emission of strong reddish long-lasting phosphorescence from the irradiated part of the glass can be observed. The emission peaks are located at 495 and 603 nm in wavelength, showing that the long-lasting phosphorescence originates from the emission of Pr~(3+). The intensity of the phosphorescence decreases in inverse proportion to time after the removal of the laser. By analysing the absorption and electron spin resonance spectra of the glass, we find that colour-centres are induced in the glass matrix after the irradiation of the femtosecond laser. A possible mechanism has been provided to account for the generation of long-lasting phosphorescence.