Single femtosecond laser pulse–induced valence state conversion in BaFCl: Sm³⁺ nanocrystals for low-threshold optical storage

Femtosecond laser-induced valence state conversion (VC) in solid materials has attracted significant research attention due to its potential application in ultra-high density optical storage, boasting advantages such as ultra-high recording speed, easy reading, and high signal-to-noise ratio. However, identifying appropriate materials and technological solutions conducive to efficient single-laser-shot recording remains a pivotal challenge for practical applications. In this work, we report single femtosecond laser pulse-induced VC in BaFCl: Sm