Transparent glass has been identified as a vital medium for three-dimensional (3D) optical information storage and multi-level encryption. However, it has remained a challenge for directly writing 3D patterning inside a transparent glass using semiconductor blue laser instead of high-cost femtosecond laser. Here, we demonstrate that rare earth ions doped transparent glass can be used as 3D optical information storage and data encryption medium based on their reversible transmittance and photoluminescence manipulation. The color of tungsten phosphate glass doped with rare earth ions change reversibly from light yellow to blue upon alternating 473 nm laser illumination and temperature stimulation, resulting in the reversible luminescence modulation. The information data could be repeatedly written and erased in arbitrary 3D space of transparent glass, not only showing the ability of the excellent reproducibility and storage capacity, but also opening opportunities in information security. The present work expands the application fields of luminescent glass, and it is conducive to develop a novel 3D data storage and information encryption media.

Reversible upconversion luminescence modification based on photochromism has received considerable interest due to its potential applications in optical storage and high‐sensitivity optical switches. However, stimulation‐induced bleaching by an external thermal field is generally used for photochromism‐induced reversible upconversion luminescence modification, which limits its practical application. In this work, a gray BaMgSiO4:Yb3+,Tb3+ ceramic is prepared, exhibiting the photochromism from gray to pink color when stimulated by 254 nm light. Interestingly, the pink BaMgSiO4:Yb3+,Tb3+ ceramic can be bleached by either a 473 nm laser or thermal stimulation. The reversible change between gray and pink color exhibits excellent reproducibility over several cycles by alternating between 254 and 473 nm (or thermal) light stimulation. The influence of the reversible photochromism of the BaMgSiO4:Yb3+,Tb3+ ceramic on its upconversion luminescence is investigated. Reversible modification of the upconversion luminescence is demonstrated by alternating between 254 and 473 nm (or thermal) light stimulation. For reversible modulation of the upconversion luminescence, excellent reproducibility is realized after several cycles. As an example, the application of the BaMgSiO4:Yb3+,Tb3+ photochromic ceramic as an anti‐counterfeiting agent is described.

Inorganic photochromic material is an available medium to obtain optical information storage. The photochromic property of the inorganic material is mainly from the defects of the host. However, the formation of defects in the host is uncontrollable, in particular, the revisable formation and removement of defects are difficult. Thus, there are few inorganic materials with the revisable photochromism upon the entire light stimulation. Therefore, it is an urgent need to find a suitable approach to design inorganic photochromic materials. Here, the photochromic PbWO 4 :Yb 3+ , Er 3+ ceramic was designed with the help of valence state change of W 6+ → W 5+ and Pb 2+ → Pb 4+ . Upon the 532 nm laser stimulation, the photochromism of the PbWO 4 :Yb 3+ , Er 3+ ceramic was obtained based on the Pb 2+ + hν (532 nm) → Pb 4+ + 2e − and W 6+ + e − + hν (532 nm) → W 5+ reaction, resulting in the optical information writing. Under the stimulation of an 808 nm laser, the written optical information was erased based on the W 5+ + hν (808 nm) → W 6+ + e − and Pb 4+ + 2e − + hν (808 nm) → Pb 2+ reaction. In addition, the photochromism-induced upconversion emission modification was obtained in the PbWO 4 :Yb 3+ , Er 3+ ceramic, realizing the effective and nondestructive reading out of optical information. The cyclic experiment demonstrated a good reproducibility of both photochromism and upconversion emission modification, exhibiting the potential application of the PbWO 4 :Yb 3+ , Er 3+ ceramic as the optical data storage medium.

Transparent glass with photochromism and luminescence has emerged as an attractive material due to its exciting prospects in the fields of information encryption and 3D optical storage. However, thermal stimulation has usually been used to bleach photochromic glass, limiting its applications. Herein, a new entirely photostimulation-induced reversible photochromic glass, doped with lanthanide ions and silver chloride (RE-Ag glass), was explored. Under the alternating stimulation of 365 nm light and a 690 nm laser, reversible photochromism (ΔR t = 91%) from transparent to black and luminescence modification (ΔR m = 93%) with high fatigue resistance were achieved in the RE-Ag glass. This is attributed to the formation and decomposition of silver nanoparticles in the glass host. The optical information can be recorded and erased in the RE-Ag glass with good rewritability and re-erasability, realizing a double-model 3D optical storage. The result highlights a new strategy to explore an entirely photostimulation induced photochromic glass with luminescence for 3D optical storage applications.

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