Multiphoton induced photoreduction in BaFCl: Sm3+nanocrystals under femtosecond laser field

Photoinduced valence state conversion in lanthanide-doped solid materials can find significant applications in areas like optical storage, opto-electronic devices and has been attracting great research efforts. Here, we experimentally demonstrate that trivalent samarium ions contained in the BaFCl nanocrystals can be efficiently reduced to divalent ones under 800 nm fs laser field. The dependences of the luminescence intensity of the photoinduced divalent ions on the femtosecond laser power, central wavelength and polarization are investigated in detail, respectively. Theoretical fits of the experimental observations indicate that a resonance-mediated (2 + 2) four-photon absorption is most probably involved in the multiphoton induced photoreduction process.

Automated summary

We experimentally demonstrate that trivalent samarium ions in BaFCl nanocrystals can be efficiently converted into divalent ions under the influence of an 800 nm fs laser field. We investigate the dependence of the luminescence intensity of the photoinduced divalent ions on the femtosecond laser power, central wavelength, and polarization. Theoretical fits suggest that a resonance-mediated (2 + 2) four-photon absorption is most likely involved in the multiphoton induced photoreduction process.