Stack-based multilayer optical storage devices with sodium silicate as bonding layers

Textual information is essential for the inheritance of human civilization; it is important to find a suitable way to preserve it. Existing information storage methods face limitations in meeting the demands of large capacity and long-term preservation of textual information. To solve these problems, this study proposes a stacked-based multilayer optical storage device utilizing laser heat-mode photoresist as recording media. The device employs lithography technology to precisely inscribe textual information onto AgInSbTe heat-mode photoresist thin films, which are deposited on ultrathin glass substrates. After clarification treatment, the textual information is retained completely, and then tens of these substrates are stacked into a multilayer optical storage device. By using an optical microscope, the information can be directly readout. A key innovation lies in the use of sodium silicate as the bonding layers among multilayers, which mitigates the adverse effects of air gaps among the multilayer structures, resulting in the improvement of image contrast. This method increases the number of layers of the device to 60, greatly improving the storage capacity. The calculation indicates that a hardware structure of of the devices can store the collection of a medium-sized library (calculated based on 100,000 volumes). Importantly, the entire process of recording and readout does not involve encoding and decoding operations, and without the issue of format expiration. This provides a new solution, to the best of our knowledge, for the large capacity and long-term preservation of textual information.