A kind of optical data storage medium based on electron-trapping materials, Y3Al5O12:Ce3+ fluorescent ceramic, was developed by vacuum sintering technology. The medium shows sufficiently deep traps (1.67 and 0.77 eV). The properties of trap levels were researched by thermoluminescence curves, and the optical storage mechanism based on Ce3+ ion doping was proposed. More importantly, the data can be written-in by 254 nm UV light, and readout by heating (300°C). This work expands the application fields of fluorescent ceramics, and it is expected to promote the development of electron-trapping materials.

A stimulated emission depletion is capable of breaking the diffraction limit by exciting fluorescent molecules with a solid Gaussian beam and quenching the excited molecules with another donut beam through stimulated emission. The coincidence degree of these two beams in three dimensions will significantly influence the spatial resolution of the microscope. However, the conventional alignment approach based on raster scanning of gold nanoparticles by the two laser beams separately suffers from a mismatch between fluorescence and scattering modes. To circumvent the above problems, we demonstrate a fast alignment design by scanning the second beam over the fabricated sample, which is made of aggregation-induced emission (AIE) dye resin. The relative positions of solid and donut laser beams can be represented by the fluorescent AIE from the labeled spots in the dye resin. This design achieves ultra-high resolutions of 22 nm in the x/y relative displacement and 27 nm in the z relative displacement for fast spatial matching of the two laser beams. This study has potential applications in scenarios that require the spatial matching of multiple laser beams, and the field of views of different objectives, for example, in a microscope with high precision.

In this Letter, a new approach of optical tape for high capacity multilayer data storage is proposed. We show that a length of 5 cm and width of 2 cm of soft and transparent optical tape can be used for two-photon three-dimensional bit data storage. We successfully demonstrate writing and reading of six layers of data storage with a transverse bit separation of 2 μm and an axial separation of 2.5 μm in a tetraphenylethylene-doped photobleaching polymer. The fluorescence intensity is insensitive to the storage depth of the photopolymer matrix. Thus, the optical tape that we put forward in the experiment can help people realize true large data storage in the future, like magnetic tape. This method significantly paves a novel way for solving big data storage problems.