Multi-level phosphor storage enabled by synergistic up-conversion and photo-stimulated trap manipulation

Phosphor-based optical storage technologies have made significant strides in encoding and decoding processes, yet persistent challenges in flexible, multi-level storage remain. Here, we present a synergistic strategy that integrates up-conversion charging (UCC) with a photo-stimulated trap manipulation (PSTM) technique to address the challenges, demonstrated through the use of co-doped Mg₃Y₂Ge₃O₁₂:Pr³⁺,Yb³⁺ storage phosphors. During the data recording phase, we employ a 450-nm laser that rapidly fills both shallow and deep traps via non-linear UCC, allowing for high-definition data recording in just 0.01 s. For retrieval, PSTM uniquely leverages ambient light to redistribute electrons from deep to shallow traps, followed by infrared-stimulated luminescence with a 960-nm flashlight to enhance data access. This UCC-PSTM synergy enables high-security, multi-level information retrieval following multi-channel data encoding, and supports numerous write/read cycles. These outcomes mark a meaningful step forward in the realm of optical storage technologies and pave the way for further developments in the field.