The launch of the big data era puts forward challenges for information preservation technology, both in storage capacity and security. Herein, a brand new optical storage medium, transparent glass ceramic (TGC) embedded with photostimulated LiGa₅O₈: Mn²⁺ nanocrystals, capable of achieving bit-by-bit optical data write-in and read-out in a photon trapping/detrapping mode, is developed. The highly ordered nanostructure enables light–matter interaction with high encoding/decoding resolution and low bit error rate. Importantly, going beyond traditional 2D optical storage, the high transparency of the studied bulk medium makes 3D volumetric optical data storage (ODS) possible, which brings about the merits of expanded storage capacity and improved information security. Demonstration application confirmed the erasable–rewritable 3D storage of binary data and display items in TGC with intensity/wavelength multiplexing. The present work highlights a great leap in photostimulated material for ODS application and hopefully stimulates the development of new multi-dimensional ODS media.

Although phosphor ceramics are promising candidates for high‐power laser lighting applications, their performance is seriously restricted by luminance saturation effects. This study proposes a novel transparent ceramic@sapphire composite material design, fabricated via a straightforward high‐temperature sintering process, which differs from the conventional approach of incorporating high‐thermal‐conductivity microcrystalline grains. This kind of composite can effectively avoid luminescence grain dilution, and deliver significantly enhanced thermal conductivity (36.9 W·m ⁻¹ K ⁻¹ ) alongside superior luminescence performance. This strategy demonstrates exceptional versatility across various ceramic systems, delivering luminescence improvements of 152–319% and enhancing luminance saturation thresholds by 100–233%, relative to traditional ceramic converters. Using Lu _2‐x CaMg ₂ Si ₃ O ₁₂ : xCe ³⁺ @sapphire as a representative example, the optimized composite enables substantial enhancements in luminous flux (5902 lm) and luminous efficacy (148 lm W ⁻¹ ) under blue laser excitation. Compared with commercial counterparts, practical applications in automotive headlights further validate the potential of this design, offering far higher luminance intensity, extended illumination distances (> 400 m), and more uniform color distribution. This study provides a scalable and universal strategy for advancing next‐generation solid‐state lighting.