China Breakthrough Promises Optical Discs That Store Hundreds of Terabytes

Optical discs that can store up to 200 TB of data could be possible with a new technology developed in China. If commercialized, it could revive optical media as an alternative to hard disk or tape for cost-effective long-term storage. The Register: Researchers at the University of Shanghai for Science and Technology (USST) and Shanghai Institute of Optics and Fine Mechanics (SIOM) say they have demonstrated that optical storage is possible up to the petabit level by using hundreds of layers, while also claiming to have broken the optical diffraction barrier limiting how close together recorded features can be. In an article published in Nature titled "A 3D nanoscale optical disk memory with petabit capacity," the researchers detail how they developed a novel optical storage medium they call dye-doped photoresist (DDPR) with aggregation-induced emission luminogens (AIE-DDPR). When applied as a recording layer, this is claimed to outperform other optical systems and hard drives in terms of areal density -- the amount of storage per unit of area. To be specific, the researchers claim it to be 125 times that of a multi-layer optical disk based on gold nanorods, and 24 times that of the most advanced hard drives (based on data from 2022). The proposed recording and retrieval processes for this medium calls for two laser beams each. For optical writing, a 515 nm femtosecond Gaussian laser beam and a doughnut-shaped 639 nm continuous wave laser beam are focused on the recording area.

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