4D Optical Information Storage from LiGa 5 O 8 :Cr 3+ Nanocrystal in Glass

With the fast‐growing amount of data, the state‐of‐the‐art optical data storage has become a front‐runner in the competing data storage technologies. However, two‐dimensional (2D) spatial resolution in the conventional optical data storage media has almost reached the limit. Herein, LiGa 5 O 8 :Cr 3+ nanoparticles (NCs) precipitated in situ from a transparent medium are prepared. The transparent LiGa 5 O 8 :Cr 3+ glass ceramics show excellent deep‐trap carriers storage ability under blue light irradiation and can realize the bit‐by‐bit optical data in 3D space for write‐in and read‐out in a photon trapping/detrapping mode. Moreover, this optical storage mechanism is also extended to 4D by realizing temperature optical encryption. Notably, the written information can still be clearly displayed even after being recorded for 200 days. This work enables 4D high‐precision storage of information and provides new insights into the design and fabrication of next‐generation storage materials.