Storage is getting denser and cheaper. Hard drives already exceed 18 TB in capacity, and memory cards and pen drives have more and more gigs. However, long-term storage is still a problem depending on what situations, since SSDs die if they are not used, and high-capacity hard drives are expensive. For this reason, a group of researchers has created a new way of storing data with a density and durability that were unthinkable until recently.
This new system has been developed by Yuhao Lei and Peter G. Kazansky , from the University of Southampton . The system makes use of high-density silica glass nanostructures. These structures are capable of storing optical data in five dimensions (5D) , with a density 10,000 higher than that of Blu-ray discs , which are currently the densest in optical format.
500 TB of data on a single disk
This high-density format can be ideal for storing long-term information for national document archives, museums, libraries, or private organizations. For cloud storage, where files need to be accessible more quickly, they would not be recommended.
The data writing system is based on two optical dimensions plus three spatial dimensions. With this, 1 million voxels can be written per second, which is equivalent to 230 KB of data per second . This is what 5 GB of data stored with this system looks like:
This is not the first case in which information has been stored in transparent materials . However, writing them quickly and at optimal density for use in the real world had become the biggest drawback to their massive extension. To fix this, the researchers used high-repeating femtosecond lasers to create tiny voids that contained a single nanolamella-like structure with dimensions of 500 by 50 nanometers each .
Thus, instead of using the laser to write directly on the crystal, the researchers harnessed the light to make use of a phenomenon called near-field enhancement . With it, the nanolamella-like structure is created using very weak light pulses , minimizing the damage caused by temperature, which is one of the biggest drawbacks encountered with previous designs.
The five-dimensional concept may sound strange, but the researchers explain it simply. As the nanostructures are anisotropic, they produce birefringence, which can be characterized by the orientation of the slow axis of light, this being the fourth dimension, which corresponds to the orientation of the structure similar to the nanolamella. The fifth dimension is the delay force, defined by the size of the nanostructure.
According to its creators, the storage system can withstand temperatures of 1,000 ºC, and last up to 13,800 million years at room temperature without degrading. The durability of today’s discs is much lower, as they can start to fail in a matter of decades.
Now they are focused on improving speed
Thanks to this system, tens of gigs of data can be written in a reasonable time. The researchers recorded 5 GB of text on a silica glass disc, with a reading of almost 100% accuracy. Each voxel stores four bits of information, and every two voxels we find a text character. With this system, 500 TB of data can be stored per disk.
The recording time is the main drawback. However, the researchers say that with improvements to the system that allow parallel writing, it is possible to write that 500 TB of data in just 60 days , at the rate of 8.33 TB per day , or about 100 MB / s .