Holographic Storage
The need for more storage is growing. The amount of data produced is doubling in every two years. (in 2010 – 1.8 zettabytes) The cost of creating, managing and storing the data is decreasing, but can the optical storage expand further?
The current Blu-ray lasers emit light in the blue part of the electromagnetic spectrum (about 420 nanometer wavelength). There are ongoing researches using UV light, that would probably have to be 200 nm and would provide storage capacities of over 100 GB in a single layer. However there are lots of commercial issues with UV optical disks, besides creating inexpensive devices to generate this wavelength of light. One of the biggest issues with working with UV is that UV is generally destructive of most plastics, so making stable long term storage could be an issue.
Since the 1960s, a new type of memory has been discussed. Holographic data storage. Sounds like it came from a Sci-fi movie; the data would be stored on a sugar cube sized plastic. This isn’t too far from reality.
It works by splitting a blue laser beam in two, a reference beam, and a data beam, which contains the information converted to binary code. Then the data beam is modulated by the SLM (Spatial light modulator – like in the digital projectors), that creates a very high density array of 1,5 million pixels.
Where the two beams intersect, a holographic interference pattern is formed. When focused on an unexposed, light sensitive holographic disk, a permanent 3D holographic image is formed in the light sensitive layer of the disk. To recover the data from the disk, a reverence laser is focused on the disk, and an image of the original array is formed and captured on a CCD sensor.
One of the main developers of Holographic storage was InPhase technologies, which produced the first commercial holographic drive and media. However, far from the data cube idea, InPhase's Tapestry system used an optical disc system, which looks similar to a DVD, held inside a caddy
The current Blu-ray lasers emit light in the blue part of the electromagnetic spectrum (about 420 nanometer wavelength). There are ongoing researches using UV light, that would probably have to be 200 nm and would provide storage capacities of over 100 GB in a single layer. However there are lots of commercial issues with UV optical disks, besides creating inexpensive devices to generate this wavelength of light. One of the biggest issues with working with UV is that UV is generally destructive of most plastics, so making stable long term storage could be an issue.
Since the 1960s, a new type of memory has been discussed. Holographic data storage. Sounds like it came from a Sci-fi movie; the data would be stored on a sugar cube sized plastic. This isn’t too far from reality.
It works by splitting a blue laser beam in two, a reference beam, and a data beam, which contains the information converted to binary code. Then the data beam is modulated by the SLM (Spatial light modulator – like in the digital projectors), that creates a very high density array of 1,5 million pixels.
Where the two beams intersect, a holographic interference pattern is formed. When focused on an unexposed, light sensitive holographic disk, a permanent 3D holographic image is formed in the light sensitive layer of the disk. To recover the data from the disk, a reverence laser is focused on the disk, and an image of the original array is formed and captured on a CCD sensor.
One of the main developers of Holographic storage was InPhase technologies, which produced the first commercial holographic drive and media. However, far from the data cube idea, InPhase's Tapestry system used an optical disc system, which looks similar to a DVD, held inside a caddy