Google Search Bar


Saturday, March 15, 2008

1 TeraByte Disk (5,000 GB)

It is called the TeraDisk and it is really small, like a ordinary CD/DVD. But it’s really huge in terms of space. 1 TB (1,000 GB). How can this be done? The process is easy (or not). All existing optical media record data on semitransparent layers. A regular CD has 1 layer and a Blu-Ray disk has up to 8. The reason nobody can add more layers on a regular CD/DVD/Blu-Ray disk is because when the light passes through these layers it becomes distorted and by the time it reaches the final layers it becomes almost impossible to read/write on the disk.

Mempile’s TeraDisc te
chnology uses specially-engineered chromophores encased within a special transparent acrylic matrix. This plastic is designed for robust commercial production using injection-molding, and for use with drive technology similar to that of DVD recorders.
Using a red laser on M
empile’s current media, the TeraDisc can record 200 DVD-like virtual layers resulting in close to 1 TB of data. With the refinements expected over time, the number of data layers will be substantially increased and other attributes like mark size and spacing decreased. Capacities of 5 TB can be expected.

More At:
Drive Components include:

CD-like system for tracking
Red read/write modelocked picosecond laser
Sensitive detector for read signal (450-600 nm)
Two dichroic elements
Focus offset control (to pick the desired working layer)
Independent servo systems for the tracking and read/write lasers
Variable spherical aberration correction

The Optical Pickup Unit

The optical pickup unit is being specially designed for precise positioning such that the head can be moved radially and vertically, always perpendicular to the recording surface. The collection and detection system is nearly standard.

The Optical and Mechanical Systems

The optical data storage industry has invested enormous resources on research and development over the last few decades, and Mempile leverages the fruits of this work in the drive design. The optomechanical systems required for disc clamping and movement, disc-head alignment, data encoding and decoding, data tracking and many other subsystems, can all be taken from existing systems with little or no modification. Even methods to lock on to and address multiple layers of information have been developed in the past (e.g. for DVD-9). The Mempile approach does not require exotic optical components previously untested in commercial optical storage, such as spatial light modulators, immersion lenses, or confocal optics. Rather, standard components are used, with the addition of a robust and simple method of variable spherical aberration correction. The use of two-photon reading means that fluorescence signal is emitted only from the addressed data point, and therefore spatial filtering optics are not required.


No comments: