Nanoscale petabyte optical memories: Past, present, and beyond

Human society has entered a rapidly evolving, intelligence-driven information age. The swift advancement of information technologies, such as big data and large-scale AI models, generates immense demand for information processing and data storage capabilities, accompanied by significant corresponding challenges. Existing data centers, built upon traditional electromagnetic storage technology, exhibit substantial limitations in terms of data storage capacity, energy consumption, cost, and sustainability. Optical data storage, with its unique advantages such as low energy consumption, cost-effectiveness, and long-term data preservation, presents a highly promising solution to the data storage demands and challenges of both the present and the future. After the background introduction, this review first introduces the development of commercial optical storage technology and summarizes its limitations. The advancements in nanophotonics technology, including super-resolution microscopy, nanolithography, and nanomaterials, are then reviewed as the basis for developing nanoscale optical storage technology. This review proceeds with a comprehensive discussion of the major technical pathways for developing high-capacity optical storage technologies: multidimensional optical storage, holographic optical storage, and super-resolution optical storage technology. Several aspects are then proposed regarding the development of the next generation petabyte intelligent optical memory technology envisioned as the future direction. Finally, this review gives a brief summary and proposes an outlook on collaborative efforts across industries to tackle the needs and challenges of optical storage technology in the AI-driven era.