Spectral phase-based valence state conversion manipulation in BaFCl: Sm³⁺ nanocrystals for multilevel information recording and display

Recent scholarly inquiry has increasingly focused on the valence state conversions of rare-earth ion-doped materials, given their promising applications in optical storage and optoelectronic devices. In this paper, we present an experimental investigation into the manipulation of valence state conversion in BaFCl: Sm³⁺ nanocrystals by modulating the spectral phases of femtosecond laser pulses for excitation with a genetic algorithm-driven self-adaptive control program. An enhancement factor of ∼1.5 and a suppression factor of ∼0.03 for the valence state conversion efficiency have been achieved. Preliminary information recording experiments substantiate the efficacy of spectral phase modulation in applications that necessitate valence state conversions. Our research not only deepens the comprehension of the photoinduced valence state conversion processes but also illustrates a potent method for modulating conversion efficiency. This approach holds significant potential for applications such as multi-level data recording and advanced display technologies.