When I was little, I had a Sony Walkman radio cassette player I loved so much and played with a lot. I also had one cassette I love playing most of the time and whenever you see me with earpiece in my ear, it is most likely to be that record that is playing. But the cassette did not last as I wanted it to cause for no reason I discovered the tape stopped producing clear sounds and the rest was stories. Magnetic tapes like the cassette has an average lifespan of 14 years (with lots of variables left as constant). The same can not be said for our computer hard drives as they have even lesser lifespan and are more fragile when compared to many other storage devices as even a sudden spike its surrounding temperature could damage it totally.
[optical drives also have very short lifespan and very fragile. Credit: pxhere]
Well say hello to the 5 dimensional data storage technology capable of storing information safely for a period approximately equal to twice the age of the earth (13.8 billion years). There’s more, it has a whooping storage capacity of 360 Terabytes and can withstand temperatures of up to 190 degree centigrade. The period of time it can store information for the stated period of time was calculated for the above temperature range but at room temperature, the storage system can store data far beyond 13.8 billion years.
Working Principle
The base element for this technology is a nanostructured glass which allows data recording in 5 dimensions, this recording is done using a process called femtosecond laser writing. Okay I’ve said a lot in just one sentence so let’s back it up a bit. Nanostructures are simply structures within the nanoscale. When describing nanostructures, the dimensions of the volume of the object is of great importance for instance nanostructured surface exists only in 1 dimension and only the thickness of the surface is considered. A typical nanostructured surface has length in the range of 1nm (a billionth of a meter) to 100nm. An example of nanostructures existing in 2 dimensions is the nanotube with diameter between 1nm to 100nm and length equal or greater than a nanoscale.
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[a femptosecond laser labcredit: wikimedia]
The emission frequencies (which defines the bandwidth of the laser) and wavelength of laser are determined by many factors like its gain medium which are basically of two types; wide spectra and linear spectra gain media. When a gain medium is composed of the type wide spectra, it allows for tuning of the laser frequency. Apart from gain medium, another factor that determines the frequency of light is the resonant cavity of the laser which comprises of two mirrors at angle 90 degrees facing each other. As light bounces between these two mirrors in the cavity, both destructive and constructive interference occur resulting in the formation of what is called MODE of such cavity.
The frequencies allowed to oscillate in the cavity are frequencies that experienced constructive interference and have the ability to regenerate itself while the frequencies that experienced destructive interference are suppressed. The period of each light pulse is determined by amount of these modes that are oscillating in phase. Credit for this technology go to the scientists at the University of Southampton and was first demonstrated experimentally in the year 2013 by writing a 300 kilobytes of text document to the glass disk.
The idea here is to store large amount of data using light in a transparent glass material which is not sensitive to light. The material that perfectly fits into this description is the fused quartz and is used as the storage element. To store data in the quartz, data is modulated by leveraging on four properties of light:
Dimensions in Data storage
We were introduced to coordinate systems in our basic levels of education. The first graph I plotted then in elementary mathematics involved joining of two points in a Cartesian plane. These two points consists of intersecting points between a point in the “y” axis and a point in the “x” axis. This is known as the two dimensional coordinate system. A more complex system is the 3 dimensional coordinate system which consists of “y” axis, “x” axis and “z” axis. Then what about the four dimensional plane system (or better still 4D space)? Does it really exist? Now we have the 5 dimensional space.
2D data storage
A typical example of 2D data storage system is the optical compact discs (CD). The CD consists of millions of tiny lines. These shiny lines are capable of bouncing back laser light that are incident on them and these reflected lights are interpreted as either ones or zeroes. To distinguish between 1 and 0, the lines have crests like square waves and troughs. When light shines on the crests, it is interpreted as ones and when light is reflected from non-crest region of the line, it is interpreted as zero.
[credit: wikimedia]
This form of storage is considered linear form of storage since just one surface is considered and can store very limited amount of data and is susceptible to physical and chemical damage with little thermal resistance.
3D data storage
As already stated above, CDs and even DVDs consists of one layer of shiny lines which can store a very limited amount of data for a very limited amount of time. 3D data storage increases both the storage capacity and storage period of 2D storage medium by increasing the layers of these reflective lines but there are problems associated with these layers as light travels in a straight line by default and hence, is bound to suffer noise as a result of interactions with these layers.
[credit: wikimedia]
To prevent this layer interaction which cause interference, 3D data storage employs a nonlinear optics in the cause of reading and writing information to the surfaces. Another way of overcoming this noise is by having these layers activated electrically when needed. A typical example of 3D storage system is the transparent compact disks (CD) or the transparent digital versatile disks (DVD) where the optical read/write head has variable depth of focus. Here, a change in the depth of focus will mean reading or recording in totally different data layer.
Not much has been said about the 4D data storage or its existence.
5D data storage
5D data storage technology differs from other forms of data storage in the sense that instead of using reflective lines, dots are imprinted on the data layers in place of these crests on the reflective lines of the 2D and 3D storage systems. These microscopic dots are known as nanogratings. These gratings have different orientations which helps prevent the issue of interference encountered in the 3D storage systems.
It is termed 5D storage system because data is encoded and decoded as a result of the orientation of the nanogratings, size of the dots and spatial dimensions of the glass (in 3 dimension). To read or decode information stored in the disk, a polarizer alongside optical microscope are used. You can view the making of this awesome tech here
[credit: optoelectronics research center]
Implications
Right from time information about technological developments and even ways of lives of different societies have been handed down from generation to generation through one failing storage medium to another. The Ten Commandments in the bible was handed down to us as inscriptions on stones, some peoples cultures were developed as a result of some drawings on caves and so on but with this technology, the United Kingdom scientists assures us that this trend don’t need to continue as information can be saved for billions of years to come in a safe non fragile glass storage medium.
As at the moment, many important documents from human development history like the Holy bible (King James Version), UDHR (Universal Declaration of Human Rights), Newton’s book on optics has been stored in the 5D storage system and was presented to the United Nations Educational, Scientific and Cultural Organization in Mexico during the International year of light ceremony.
Conclusion
The 5D data storage system as at the time of compiling this post can store up to 360TB of data under temperature of 190 degrees centigrade for 13.8 billion years. The application of such technology can easily be figured out and could have many positive implication for future computing. Currently, the the technology has not been commercialized but the geniuses at the University of Southampton, UK promisses that this would be a reality in the nearest future.
Reference
- 5D data storage -theverge
- the new 5D data storage
- 5D optical data storage -wikipedia
- 5D data storage update -southampton.ac
- 5D data storage, how does it work? -allaboutcircuits
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