The leap from standard 4.7GB DVDs to massive 50GB Blu-ray discs seemed like an incredible jump, but researchers have recently made a breakthrough that positively dwarfs that increase in storage capacity, by cramming a petabyte (1000 TB) of data onto a single DVD, making those 100 Movie Packs at Best Buy look paltry by comparison.
According to a new paper published in Nature, the kind of lasers traditionally used to burn DVDs and Blu-rays is limited to being focused to half their wavelength. In the case of DVD, that’s about 650 nanmoeters; for Blu-ray Disc, 405 nanometers. That lower limit also puts constraints on how small each bit of data can be. If one bit takes up a certain finite amount of space, there are only so many bits you can fit onto a five-inch disc.
By combining two lasers, though, researchers Zongsong Gan, Yaoyu Cao, Richard A. Evans, and Min Gu have created a 3D writer in which one beam — a donut-shaped purple laser ring — selectively cancels out part of the other, more traditionally shaped red round beam, allowing for an infinitesimally small focal spot of nine nanometers. Smaller focal spot means more bits per surface area. And that’s how you cram a petabyte of data onto a five-inch disc.
Before you get too excited, there is currently no consumer device capable of reading the data, nor is there likely ever to be. It’s unlikely that we’ll see this technique used anytime soon for commercial discs (especially given the prevailing notion in the entertainment industry that discs are dead). If anything, this will likely serve as a base for three-dimensional data storage in the future, as a sort of archival format.
Via: [The Conversation]