The 9.4-gigabyte capacity on a standard double-sided DVD is enough to hold a motion picture in two formats and perhaps some outtakes and extras. But for years researchers have been looking for a way to cram even more data on a disc of the same size. One idea that’s been perpetually just around the corner is holographic data storage on a holographic versatile disc, or HVD. Instead of marking pits and grooves on the surface of the disk that are subsequently read by a laser, the technique uses special materials that chemically change the entire volume of the disc when it’s zapped by a laser in the ”write” stage. Using the entire thickness of the disc yields hundreds of times more storage capacity.

Now GE Global Research says it has hit upon a polycarbonate material that can be manipulated to store 500 GB on a single DVD. The breakthrough was figuring out how to create holographic pits and grooves one micrometer across with enough reflectivity to allow the laser light to bounce back to the sensor that reads the bits of data.

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From WinZips to Cat GIFs, Jacob Ziv’s Algorithms Have Powered Decades of Compression

The lossless-compression pioneer received the 2021 IEEE Medal of Honor

11 min read
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Photo of Jacob Ziv
Photo: Rami Shlush
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Lossless data compression seems a bit like a magic trick. Its cousin, lossy compression, is easier to comprehend. Lossy algorithms are used to get music into the popular MP3 format and turn a digital image into a standard JPEG file. They do this by selectively removing bits, taking what scientists know about the way we see and hear to determine which bits we'd least miss. But no one can make the case that the resulting file is a perfect replica of the original.

Not so with lossless data compression. Bits do disappear, making the data file dramatically smaller and thus easier to store and transmit. The important difference is that the bits reappear on command. It's as if the bits are rabbits in a magician's act, disappearing and then reappearing from inside a hat at the wave of a wand.

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