Direct writing-in and visualizing reading-out data storage with high capacity in low-cost plastics

Abstract

Abstract The explosive growth of the global data volume demands new and advanced data storage methods. Here, we report that data storage with ultrahigh capacity (~1 TB per disc) can be realized in low-cost plastics, including polycarbonate (PC), precipitated calcium carbonate (PCC), polystyrene (PS), and polymethyl methacrylate (PMMA), via direct fs laser writing. The focused fs laser can modify the fluorescence of written regions on the surface and in the interior of PMMA, enabling three-dimensional (3D) information storage. Through the 3D laser processing platform, a 50-layer data record with low bit error (0.96%) is archived. Visual reading of data is empowered by the fluorescence contrast. The broad variation of fluorescence intensity assigns 8 gray levels, corresponding to 3 bits on each spot. The gray levels of each layer present high stability after long-term aging cycles, confirming the robustness of data storage. Upon single pulse control via a high-frequency electro-optic modulator (EOM), a fast writing speed (~1 kB/s) is achieved, which is limited by the repetition frequency of the fs laser.