Scientists create 1.6-petabit optical storage disc

Are optical discs obsolete? Don’t be so quick to say obvs.

Researchers from the University of Shanghai for Science and Technology, the Shanghai Institute of Optics and Fine Mechanics, and other Chinese institutions announced in February that they’ve demonstrated a way to pack more than a petabit of data (125 terabytes) into one optical disk. That’s larger than the world’s biggest hard drive, a $40,000 goliath which can hold 100 terabytes.

Previous optical storage methods, like CD-ROMs, DVDs, and Blu-rays, store data in one, two, or even four layers. The researchers claim new advances in optical technology, most centrally an ultra-transparent film called “aggregation-induced emission dye-doped photoresist” (AIE-DDPR), allow them to encode data on as many as 100 layers and achieve 1.6 petabits (200 terabytes) of storage on a single disc of typical size.

Using AIE-DDPR in combination with dual lasers, the scientists reported they were able to blow past the optical diffraction limit—as ZME Science explained, that’s the smallest point an optical imaging system can resolve. Historically, that’s been limited to around the size of the wavelengths of light produced by an optical device.

The Chinese researchers said that by tightly controlling the firing times of two sets of dual lasers used for reading and writing to the disc, and using the AIE-DDPR film, they were able to encode and read data from spots roughly one-tenth the wavelength of the visible light used in the optics. Each of the 100 layers on the disc is separated by about one micrometer and, according to the study, all of the layers have comparable write quality.

“It has been a 10-year effort searching for this kind of material,” Min Gu, a University of Shanghai professor of optical-electrical and computer engineering, told IEEE Spectrum. “The difficulty has been how the writing and reading processes affect each other in a given material—in particular, in a three-dimensional geometry.”

Gu added he was surprised the material handled both writing-recoding and reading at the nanoscale level well. According to IEEE Spectrum, the researchers say the discs can likely be manufactured in about six minutes apiece using similar processes to DVDs.