摘要
The ability to manipulate the valence state conversion of rare-earth ions is crudal for their applications in color displays, optoelectronic devices, laser sources, and optical memory. The conventional femtosecond laser pulse has been shown to be a well-established tool for realizing the valence state conversion of rare-earth ions, although the valence state conversion efficiency is relatively low. Here, we first propose a femtosecond laser pulse shaping tech- nique for improving the valence state conversion effidency of rare-earth ions. Our experimental results demonstrate that the photoreduction emciency from Sm3＋ to Sm2＋ in Sm3＋-doped sodium aluminoborate glass using a zt phase step modulation can be comparable to that using a transform-limited femtosecond laser field, while the peak laser intensity is decreased by about 63%, which is very beneficial for improving the valence state conversion efficiency under the laser-induced damage threshold of the glass sample. Furthermore, we also theoretically develop a （2 ＋ 1） resonance-mediated three-photon absorption model to explain the modulation of the photoreduction efficiency from Sm3＋ to Sm2＋ under the π-shaped femtosecond laser field.
The ability to manipulate the valence state conversion of rare-earth ions is crucial for their applications in color displays, optoelectronic devices, laser sources, and optical memory. The conventional femtosecond laser pulse has been shown to be a well-established tool for realizing the valence state conversion of rare-earth ions, although the valence state conversion efficiency is relatively low. Here, we first propose a femtosecond laser pulse shaping technique for improving the valence state conversion efficiency of rare-earth ions. Our experimental results demonstrate that the photoreduction efficiency from Sm^(3+) to Sm^(2+) in Sm^(3+)-doped sodium aluminoborate glass using a π phase step modulation can be comparable to that using a transform-limited femtosecond laser field, while the peak laser intensity is decreased by about 63%, which is very beneficial for improving the valence state conversion efficiency under the laser-induced damage threshold of the glass sample. Furthermore, we also theoretically develop a(2 + 1)resonance-mediated three-photon absorption model to explain the modulation of the photoreduction efficiency from Sm^(3+)to Sm^(2+)under the π-shaped femtosecond laser field.
基金
National Natural Science Foundation of China(NSFC)(11474096,11727810,11774094,61720106009)
Science and Technology Commission of Shanghai Municipality(STCSM),China(16520721200,17ZR146900)
