The Future (In Brief)

Many technologies are being studied as possible replacements or substitutes for the storage methods now in use.


Further developments in Magneto Optical Storage
 
 
Magneto-Optical storage using solid immersion lenses (SIL) is being developed by a company in San Jose called TeleStor.  What the SIL allows is focusing the laser beam on a much smaller area, allowing much higher data densities.

A note about SIL's:  Solid Immersion Lenses are a special type of truncated spherical lens invented at Stanford University.  SIL's use liquid-immersion microscopy (a magnification technique), but in reverse, allowing it to focus a laser beam on a spot smaller than one micron.

Patterned media
 

 

 Another technology under study is that of "patterned media."  This actually entails creating a surface with literally billions of small hills or mesas on which bits would be recorded.  This is done to isolate the magnetic fields from one another, preventing interference from the magnetic patterns of other bits.  While current technologies require 500 to 1000 grains for each bit, a patterned media disk may only require seven to eight grains per bit.  This could allow up to ten terabits per square inch.  Right now, this approach does not work, because the technology does not exist to create media with small enough mesas: the need is mesas of eight nanometers; the current limits of lithographic process is 80 nanometers.

Holographic Storage

Explaining holographic storage could be a project in an of itself, in fact, it is.  So, I will attempt to be brief.  A holographic crystal allows data storage in three dimensions, since holograms not only record light, but it's direction as well.  In addition, because holograms are created using a reference beam to generate an image, several different data records can be stored in the same location using a slightly different reference beam.  This allows extremely high data densities: the eventual goal is to enable a data storage of one terabyte (one trillion bytes, or eight trillion bits) per cubic centimeter.  So far, the achievements to date have garnered 48 megabytes per cubic centimeter.  But, this is encouraging, and research continues.  Since trying to go into great detail would result in a several page addition, I will refer the reader to this excellent project, or this article at the Scientific American.

Atomic Resolution Storage
 
 
Atomic resolution storage involves the actual manipulation of spots as small as a few nanometers across.  The technology, like that of CD-RW, operates on phase changes.  To write data, the field emission tip ejects a stream of electrons, heating a spot on the recording cell, and changing it to the appropriate phase, either amphorous or crystalline.  Then to read the data, the phase is check either optically, or by measuring the resistance of the spot.  This technique may allow data densities up to one trillion bits per square inch.  While nowhere close to that of holographic data storage, ARS could be used where space and power concerns are paramount, such as watches, phones, or other embedded systems.

Wow, with all that, we certainly need a conclusion...