HOLOGRAPHIC DATA STORAGE

-N.P.GANESH

Overview... Introduction What is HDS? How does it work? System Recording and Reading the Data Storage Medium Uses of the System Cons and Pros Conclusion

Introduction Generally a Hologram is a 3D image

reproduced from a pattern of interference.

The Holography technique was invented in 1948 by the Hungarian Dennis Gabor.

Evolving in the last few years. Promise to be the data storing system of

the future.

Introduction Holographic Data Storage is an

advanced data storage concept that stores information in the form of holographic images.

Holographic Data Storage is a volumetric approach of storing data.

An HDSS can store 1-4 TB of data on a sugar-cube sized crystal.

Hologram The word Hologram is derived from a

Greek word ‘HOLOS’ meaning whole and ‘gram’ meaning message.

It tells information about size , shape, brightness and contrast of object being recorded.

It is a 3D image formed by the interference of light beam from a laser or other coherent light source.

Hologram  Typically, a hologram is a photographic

recording of a light field, rather than of an image formed by a lens.

It is used to display a fully three-dimensional image of the holograph subject, which is seen without the aid of special glasses or other intermediate optics.

Holography is the science and practice of making holograms. 

What is Holographic Data Storage? Holographic data storage is a potential

technology in the area of high-capacity data storage currently dominated by magnetic data storage and conventional optical data storage

Storage System in which two beams from the same laser source are used to record the data into a ‘recording medium’.

Technology uses holograms which are created when a light from a single laser beam is split into two beams

HOW DOES IT WORKS?

Uses a reference beam and data beam to create an interference pattern While Writing: The intersection

of the two beams causes a change , which is then stored

While Reading Action of the

reference beam and interference pattern is used to recreate the data beam

The System Basic components of System: Laser Recording Medium Mirrors Spatial light modulator Beam splitter Shutters Iris Lenses Half-wave plate

Recording The Data Holographic data storage contains information

using an optical interference pattern within a thick, photosensitive optical material

Light from a single laser beam is divided into two, or more, separate optical patterns of dark and light pixels.

By adjusting the reference beam angle, wavelength, or media position, a multitude of holograms (theoretically, several thousand) can be stored on a single volume.

Reading The Data The stored data is read through the reproduction of the

same reference beam used to create the hologram. The reference beam's light is focused on the

photosensitive material, illuminating the appropriate interference pattern, the light diffracts on the interference pattern, and projects the pattern onto a detector.

The detector is capable of reading the data in parallel, over one million bits at once, resulting in the fast data transfer rate.

Files on the holographic drive can be accessed in less than 0.2 seconds.

Uses of the System Can be used to store any kind of

information from documents to videos. Other fields that uses this system are: Government sectors Libraries Business and more

Storage Medium There are mainly two storage mediums used:

Lithium-Niobate Crystal PhotopolymerMedia Parameters:1.Diffraction efficiency2.Holographic fidelity3.Sensitivity4.Dynamic Range5.volatility

Holographic versatile disc HVD is an optical disc technology still in

the research stage which would hold up to 3.9TB of information.

It employs a technique known as Collinear Holography where by two lasers one red and one blue green are collimated in a single beam.

which is approx. 6000 times capacity of CD-ROM,830 times capacity of DVD-ROM and 160 times capacity of BLU-Ray disc and 8 times capacity of computer hard drives.

Transfer Rate:1 GB/sec.

Comparison of HVD with other Storage devices

Pros:**Storage Capacity High density small volume**Effective Rapid data rate fast access**Swift Searching**Security**Parallel access**Longer Storage Life

Cons Sensitive Material limitations Noise Cost Problems with parallel recording

Conclusion Holographic Data Storage is convenient

and effective way of data storage. The HVD playing device would have

data rates 25 times faster than today’s fastest DVD players.

-GANESH NETHI