Nonvolatile plasmonic holographic memory based on photo-driven ion migration

Stability of data storage is essential for optical information processing. TiO2 nanoporous films loaded with small-sized Ag nanoparticles thus attracted much attention due to their fast and polarization-sensitive photochemical response, which is able to realize optical phase modulation and high-density optical memory. However, little attention was given to the modulation of the silver ion migration, which plays a key role in anti-erasure of the recorded hologram. In this paper, the strong coupling of two phase gratings was achieved by long-term recording in the Ag-TiO2 film irradiated with a pair of coherent left- and right-hand circular polarization lights from a Blu-ray (∼405  nm) laser. The migration of Ag+ ions was enhanced by the electronic field gradient force. A stable polarization holographic grating was obtained by this method and observed by a polarizing microscope. This work provided a strategy for a nonvolatile device based on photo-driven ion migration.