A group of researchers at the University of Southhampton in the UK have invented a new type of optical recording, based on femto-second laser pulses and silica/quartz media that can store up to 300TB per (1″ diameter) disc platter with thermal stability at up to 1000°C or a media life of up to 13.8B years at room temperature (190°C?). The claim is that the memory device could outlive humanity and maybe the universe.
The new media/recording technique was used recently to create copies of text files (Holy Bible, pictured above). Other significant humanitarian, political and scientific treatise have also been stored on the new media. The new device has been nicknamed “Superman Memory Crystal”, due to the memory glass (quartz) likeness to Superman’s memory crystals.
How it works
Data is recorded in three layers of dots, separated by five micrometres (10E-6 meters) in depth, inside the quartz crystal. The data is recorded in self-assembled nano-structures inside the fused quartz.
Recording is in 5 dimensions, i.e., the 1) size of dots; 2) orientation (polarization) of the dots; and 3-5) the layer of quartz the dot lies in. The dots are made with a super fast, femtosecond (10E-15 seconds) laser pulse. Each dot in a layer effectively encodes 3 bits of information. The data can be read out by an optical microscope and a polarizing filter.
The technical paper on the 5D storage shows the laser path for the write path and uses a femtosecond laser, spatial light modulator, fourier (frenzel) lens, dichroic mirror, 1/2 wave plate matrix, and 1.2NA water immersion to record the dots]’s in 3 layers onto the silca-glass media. Read path used a BX51 optical (Olympus, Inc.) quantitative based birefringence system that would reveal both the slow axis and retardance distribution of the dot layer. The paper include a picture of a a small segment readout of one of the layers at 60X magnification microscope with side-by-side views of slow axis and retardance information. [Not sure what any of the previous description actual means but it should describe the optical write and read path, to someone in the know].
Not sure why the need for the femtosecond laser unless there’s potential for recording media dot smear/clarity with longer lasers pulses. The original article cited above, has a short video showing the lab device recording onto a square of silica.
Future uses for the new recording device/media
No description on the text encoding used on the recordings that were made, but it probably was a version of UTF-? or ASCII. But if the recording device is as dense as indicated, there’s no reason it needs to be limited to text. And with 5 dimensions, I am sure we could come up with a way to record pictures, audio, and potentially motion pictures in an analog format, directly into the media without even having to encode it digitally into JPG/MP3/MP4 files, whichever provides the best resolution and density.
Moreover, Unclear why the device has to record on a disc as the recording video showed a square of material and a linear track recording. A circular disc could be a better form factor for faster read and write. But a square or rectangular form factor might be even more advantageous for personal, corporate and legal use as a recording media for manual filing.
I could see the device providing a sort of audio/visual/biological historical recording of a person that could be used in conjunction with a, in place, person’s audio/visual/biological scan, as a sort of security token for computer and physical access security.
Not sure whether the device, once recorded to, can be extended, or if the data recorded onto the silica can be added to. If so, this would make a great device to record medical records, scans and other biological assays that a person could keep as a copy of their own medical records, in addition to the medical recordings kept in the medical provider’s office. And if it would work for medical records, there’s no reason it couldn’t also work for corporate information archives, court proceedings, body camera video, etc.
However, it depends on the speed of recording to the device if it’s to be used as a general purpose information archive and not all electronic information has to live 13.8B years. Also, from an corporate, judicial and personal archive perspective the playback speed or read bandwidth off the device matters too. I could not see any information on read-write bandwidth, track seek times or IOs per second for the new device. With over 300TB per 1″ diameter disc, it could take a looooong time to fill up one disc.
Finally, the question on encoding formats and format changes is a constant and enduring problem for any really long term archive. Yes ASCII and UTF-32 may be current and fairly persistent formats today, but in a 1000 years who knows. And JPG, PDF, MP3, MP4 are all fairly recent formats, that seem to be updated periodically for better resolution, higher density or other efficiency purposes. So these formats, although may be well known currently, would need to be somehow frozen, to insure they were readable over 1000 let alone Billions of years.
Or we would need a encoding format definition/cross-translation device, like the Rosetta stone, that could be strategically stored, in multiple archives around the world, that details the definition of the encoding format in a baseline (textual, XML, ?) format. Maybe this translation information, could be made a part of each and every recording on a disk the device produces. It certainly wouldn’t take much space to add an XML description of the formats used in recordings stored on the device, especially if it holds 300TB.
At this point the recording, read back and silica glass media are lab experiments but have recorded multiple text files, across multiple discs and have publicised all the technology behind it.
The research team is currently looking for partners to commercialize the technology if anyone’s interested. Sounds very interesting from my perspective.
Photo Credit(s): Southhampton website, The Verge article on the technology, Physics world article on the technology, All About Circuits article on the technology, and Thomas Quine, Rosetta Stone Detail