We report on near infrared to visible upconversion luminescence in Tb3+-doped SrO-TiO2-SiO2 glass excited at 800nm by using femtosecond laser irradiation. The luminescence spectra of the glass are similar for femtoseeond laser irradiation and excitation at 267nm with a Xe lamp. The upconversion lumi-nescence can be assigned to 5D3→7F4 and 5D4→7FJ(J=6, 5, 4, 3) transitions of Tb3+. The relationship between the emission intensity of Tb3+ and the pump power indicates that a three-photon simultaneous ab-sorption process is dominant in the conversion of infrared to the green luminescence. We suggest that the simultaneous absorption of three infrared photons promotes the Tb3+ to excited states, which quickly cas-cade down to lower excited states, and radiatively relax to terminal states, resulting in the characteristic fluorescence of Tb3+. This has promising applications in three dimensional display, visible lasers and high-resolution optical data storage.%Tb3+ 掺杂SrO-TiO2-SiO2 玻璃在 800nm 的飞秒激光照射下可以观察到红外至可见的上转换现象.由飞秒激光激发的上转换荧光光谱与 267 nm 氙灯激发的荧光光谱非常相似.其上转换荧光可归因于Tb3+的5D3→7F4和5D4→7FJ(J=6,5,4,3)能级跃迁.由发光强度和泵浦光源能量之间的关系可以得出此上转换过程为三光子同时吸收过程.基态电子同时吸收三个红外光子被激发到较高激发态,然后以非辐射跃迁方式弛豫到较低激发态,再辐射跃迁到基态从而产生 Tb3+ 的特征发光峰.这现象可应用于三维立体显示,可见激光和高密度光存储技术.
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