Laser-direct-writing of molecule-like Ag nanoclusters in transparent tellurite glass for 3D volumetric optical storage.

constructing program-designed nanostructures laser-direct-writing (LDW) has proved to be a reliable strategy for optical storage (OS). Herein, a kind of low-melting Ag-doped TeO-ZnO-NaO (TZN) tellurite glass has been demonstrated as an ideal LDW OS medium. Microstructural and spectroscopic studies reveal the generation of molecule-like Ag nanoclusters featured with a broad emission band in the orange-red region upon laser irradiation. Probing the laser-glass interaction yields evidences of the spatial distribution of Ag species responsive to laser-induced thermoelastic pressure wave oscillation, as well as the heat-driven migration/aggregation of Ag species along the radial direction of the laser spot. Raman analyses disclose the loose network of TZN-glass convenient for Ag mobility and the increased network connectivity when Ag nanoclusters are precipitated out. Combined with the XPS result of Ag → Ag reduction, the possible formation mechanism of Ag nanoclusters stabilized in glass has been proposed. In a proof-of-concept experiment, 3D volumetric OS in the TZN glass has been demonstrated, showing optical data encoding/decoding in the form of characters and image patterns.