Plasmon-mediated multi-wavelength optical storage in rare-earth hybrid nanocomposites

Next-generation optical data storage demands materials that support reversible and high-contrast luminescence switching across multiple wavelengths. In this study, we developed hybrid systems integrating rare-earth-doped nanocrystals (Eu 3+ or Yb 3+ /Er 3+ ) with tunable silver nano-islands films designed to exhibit either narrowband or broadband plasmonic absorption. The plasmon-driven photothermal effect facilitates reversible phase transitions in the host matrix and enables efficient modulation of luminescence, demonstrating wavelength-selective switching with narrowband absorbers and broad-wavelength response with broadband absorbers. Notably, we achieved cross-wavelength optical information storage using near-infrared light (800/980 nm) for writing and visible light (532 nm) for reading. Finite element simulations provide insight into the photothermal mechanisms and spatial temperature distributions, indicating that narrowband absorption induces localized hot spots, while broadband absorption results in spatially distributed heating. This work establishes a material platform and mechanistic foundation for high-security optical storage, anti-counterfeiting technologies, and multiplexed photonic devices.