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

"So once the data is safely inside the glass, it's good for a really long time, said Richard Black, the research director of Project Silica. Writing in the journal Nature, Black and colleagues report how the system works by turning data in the form of bits into groups of symbols, which are then encoded as tiny deformations, or voxels, within a piece of glass using a femtosecond laser. Several hundred layers of these voxels, Black notes, can be made within 2mm of glass."

"The system uses a single laser pulse to make each voxel, making it highly efficient. By splitting the laser into four independent beams writing at the same time, the team say the technology can record 65.9m bits per second. The researchers found they could store 4.84TB of data in a 12 sq cm piece of fused silica glass, 2mm deep about the same amount of information that is held in 2m printed books, an accompanying article by researchers in China notes."

Digital archives currently depend on magnetic tape and hard disks with limited lifespans, requiring repeated copying to new media. Laser-writing in fused silica encodes bits as groups of symbols that are inscribed as tiny deformations, or voxels, using a femtosecond laser. Several hundred layers of voxels can be produced within 2 mm of glass, with a single laser pulse creating each voxel for high efficiency. By splitting the laser into four simultaneous beams the system can record about 65.9 million bits per second. Demonstrations stored 4.84 TB in a 12 sq cm, 2 mm deep glass sample, equivalent to roughly two metres of printed books. The glass medium offers extreme durability and longevity for long-term preservation.

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