Stone, parchment or laser-written glass? Scientists find new way to preserve data | Technology

Some cultures used stone, others parchment. Some even used floppy disks for a time. Now scientists have developed a new way to protect archived data that they say could last for millennia: laser writing on glass.

From personal photos kept for life to professional documents, medical information, data intended for scientific research, national archives and heritage data, there is no shortage of information that must be kept for very long periods.

But there’s a problem: Current long-term storage of digital media – including in data centers that support the cloud – relies on magnetic tapes and hard drives, both of which have a limited lifespan. This means that repeated cycles of copying to new tapes and disks are necessary.

Now Microsoft experts in Cambridge claim to have perfected a method of long-term data storage based on glass.

“It has incredible durability and longevity. So once the data is safe inside the glass, it’s retained for a very long time,” said Richard Black, research director of the Silica Project.

Writing in the journal Nature, Black and colleagues explain how the system works by transforming data – in the form of bits – into groups of symbols, which are then encoded as tiny deformations, or voxels, in a piece of glass using a femtosecond laser. Several hundred layers of these voxels, Black notes, can be produced within a radius of 2 mm of glass.

The system uses a single laser pulse to create each voxel, making it very efficient. By splitting the laser into four independent beams writing at the same time, the team says the technology can record 65.9 million bits per second.

The researchers found they could store 4.84 TB of data in a 12 cm² piece of fused silica glass, 2 mm deep – roughly the same amount of information contained in 2 million printed books, notes an accompanying article by Chinese researchers.

The team also developed a way to create voxels from borosilicate glass, the material used by the Pyrex brand.

“It’s much more commonly available, it’s much cheaper, it’s easier to manufacture,” Black said.

Once written, the voxels can be read by scanning the glass under an automated microscope equipped with a camera to capture images of each layer. These images are then processed and decoded using a machine learning system.

“All steps, including writing, reading, and decoding, are fully automated, allowing for robust, low-effort operation,” the team writes.

They add that the data storage system is very stable, with experiments suggesting that the deformations created by the laser would last more than 10,000 years at room temperature.

However, Black said the technology was unlikely to end up in a home office, instead noting that the system was intended for use by large cloud computing companies.

Melissa Terras, professor of digital cultural heritage at the University of Edinburgh, who was not involved in the work, welcomed the study.

“Any type of storage that allows for long-term management of digital information is exciting, particularly if the medium is inert and has the potential to last without special maintenance,” she said.

But, she added, potential challenges remain, including whether the instructions and technology to read glass will remain available for future generations.

And there’s another problem: Significant investments would be required to deploy Silica on a large scale. “We are not in an economic period where industry or politics chooses to build infrastructure that will meet the information needs of future generations,” Terras said.

“I would recommend that if this were a problem, we should devote our scarce resources to repairing the consequences of the cyberattacks on the British Library, to ensure that the information we already have in known formats is managed and available to users, now and in the future.”