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Science communication is important in today's technologically advanced society. A good part of the adult community is not science saavy and lacks the background to make sense of rapidly changing technology. My blog attempts to help by publishing articles of general interest in an easy to read and understand format without using mathematics. I also give free lectures in community events - you can arrange these by writing to me.

Saturday, 20 February 2016

A Promising Development - Eternal 5D Data Storage in Fused Quartz

This post involves a number of prefixes on units which not everybody will be familiar with  
These are explained in the slide at the end of the post
Blog Contents - Who am I?

Scientists at the Optoelectronics Research Centre (ORC) at Southampton University have taken a significant step in solving the problem of archiving large amounts of data

What Have They Done? -   Developed the recording and retrieval processes of digital data by femtosecond laser writing on fused silicaTheir portable memory storage has data capacity of up to 360 Terabyte per disc, is thermally stable to 1,000°C and has virtually unlimited lifetime at room temperature (13.8 billion years at 160°C ).  
The technology could be used by organisations with big data storage requirements, such as national archives, museums and libraries, to preserve their information and records.
How is big data stored at present and why do we need bigger storage capacity? -  At the moment, the longest-lasting storage technology in the world is the  M-Disc which uses Blu-Ray technology to store data for up to 1,000 years.  For personal data storage - flash disc storage lasts for a few years.
However, most data centers handling large amount of data use hard-disc drives (HDD) which are expensive for loading data.   HDD are unsuitable for long-term storage and require transferring of data about every two years. 

Total capacity of data stored has been increasing by about 60% each year and we shall need to manage 40000 Exabyte of data by 2020.  HDD  power consumption is of the order of 0.04 Watt per Gegabyte of data stored.  The power consumption of American data centers alone is expected to reach 140 billion kWh (one kWh is equal to one unit of electricity) per year costing $14 billion @10 cent per unit.
What is needed is a less expensive way to store data which can stay secure for a very long time.  
This is exactly what scientists at OCR have achieved in their new storage device combining the best of laser and nano-technologies (NT). For an introduction to NT for non-specialists, you can look at my course notes available here.  Talk-5 deals with digital revolution. 
What is the Technology? -   (I am much obliged to ORC for providing me a clear description of their technology).  Ultrafast laser induced nanogratings in fused quartz, the key of the eternal 5D memory storage system, were first discovered by Professor Peter Kazansky at ORC. These nanogratings exhibit some extraordinary properties such as extremely high thermal and chemical stability, as well as ability to manipulate transmitted light.
In conventional optical media, such as DVDs, the data is stored by burning tiny pits on one or more layers on the plastic disc using three spatial dimensions. When the data-recording ultrafast laser marks the glass, it doesn’t just make a pit. It makes a pit with the self-assembled nanogratings that are the smallest embedded structures ever produced by light. The orientation (4th dimension) and strength (5th dimension) of these nanogratings implemented as two additional parameters increase the amount of digital data held per pit. During retrieval, these 2 extra dimensions also interact with oncoming light, modulating the transmitted light from which we can derive the information stored in the 5-dimensions. The estimated ultimate capacity, which could be achieved with the 5D data storage technology, is 360 TB per disc.

The recording system uses an ultrafast laser to produce extremely short (femtosecond - a million billionth of a second) intense laser pulses of light. The file is written in up to 18 layers of nano-structured dots separated by 5 micrometers in fused quartz.  The self-assembled nanostructures change the way light travels through glass, modifying the polarization of light, which can then be read by an optical microscope, and a  polarizer similar to that found in polaroid sunglasses.

What is the future? -  As with any new technology, it takes time to reach maturity and practical demonstration is important.  OCR have already demonstrated the efficacy of 5D data storage by writing some important documents on their glass discs.
The next step is obviously to commercialize the technology for wider uptake.  
The places where I see 5D storage to be most useful is in data archiving.  I am not sure how expensive the retrieval system will be with state of art laser systems required.  

As I have been emphasizing in my publications, the new technologies are progressing rapidly and delivering marvelous new inventions/discoveries.  But, it is in the synergy that the real promise lies - where two or more of the new technologies come together and yield benefits far in excess of what any one of them could have hoped to achieve individually.

Post Script:  When I first read the research as 5D Data Storage, I started to figure out what the five dimensions could be.  Physicists understand the three space dimensions and they are happy to accept the fourth dimension of time.  Space-time form the four dimensions as far as physics is concerned.  Obviously technologists do not follow the same nomenclature and that causes confusion.  3D printing was fine but now we have 4D printing also.  5D data storage uses three dimensions of space and two parameters of nanogratings in fused quartz.  I would have called the system 3D2P storage.  Just a thought - apologies if this does not go down well.  
Prefixes for units

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