The ongoing quest for higher data storage density has led to a plethora of innovations in the field of optical data storage. This review paper provides a comprehensive overview of recent advancements in next-generation optical data storage, offering insights into various technological roadmaps. We pay particular attention to multidimensional and superresolution approaches, each of which uniquely addresses the challenge of dense storage. The multidimensional approach exploits multiple parameters of light, allowing for the storage of multiple bits of information within a single voxel while still adhering to diffraction limitation. Alternatively, superresolution approaches leverage the photoexcitation and photoinhibition properties of materials to create diffraction-unlimited data voxels. We conclude by summarizing the immense opportunities these approaches present, while also outlining the formidable challenges they face in the transition to industrial applications.

Long-term optical data storage (ODS) technology is essential to break the bottleneck of high energy consumption for information storage in the current era of big data. Here, ODS with an ultralong lifetime of 2×10⁷ years is attained with single ultrafast laser pulse induced reduction of Eu³⁺ ions and tailoring of optical properties inside the Eu-doped aluminosilicate glasses. We demonstrate that the induced local modifications in the glass can stand against the temperature of up to 970 K and strong ultraviolet light irradiation with the power density of 100 kW/cm². Furthermore, the active ions of Eu²⁺ exhibit strong and broadband emission with the full width at half maximum reaching 190 nm, and the photoluminescence (PL) is flexibly tunable in the whole visible region by regulating the alkaline earth metal ions in the glasses. The developed technology and materials will be of great significance in photonic applications such as long-term ODS.Long-term optical data storage (ODS) technology is essential to break the bottleneck of high energy consumption for information storage in the current era of big data. Here, ODS with an ultralong lifetime of 2×10⁷ years is attained with single ultrafast laser pulse induced reduction of Eu³⁺ ions and tailoring of optical properties inside the Eu-doped aluminosilicate glasses. We demonstrate that the induced local modifications in the glass can stand against the temperature of up to 970 K and strong ultraviolet light irradiation with the power density of 100 kW/cm². Furthermore, the active ions of Eu²⁺ exhibit strong and broadband emission with the full width at half maximum reaching 190 nm, and the photoluminescence (PL) is flexibly tunable in the whole visible region by regulating the alkaline earth metal ions in the glasses. The developed technology and materials will be of great significance in photonic applications such as long-term ODS.

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.