Contents 1. Introduction. 2. What is Holographic memory? 3. What is HVD? 4. Structure of HVD. 5. How HVD Works? I. Writing Data II. Reading Data 6. Advantages of HVD 7. Limitations AND Challenges 8. How HVD compares with other storage device? 9. Conclusion
Introduction A hologram is a 3D image reproduced form a pattern of interference. The Holography technique was invented in 1948 by the Hungarian Dennis Gabor. It can store up to 1-4 TB of information in a sugar cube sized crystal. It promises to be the data storing system of the future. Hence holographic storage system has the potential to became the next storage generation over conventional storage system.
What is Holographic Memory? Holographic memory is a three-dimensional data storage system that can store information at high density inside the crystal or photopolymer. It is a memory that can store information in the form of holographic image (hologram) Like other media, holographic media is divided into write once (where the storage medium undergoes some irreversible change), and rewritable media (where the change is reversible).
HolographicVersatile Disc These discs have the capacity to hold up to 3.9 terabyte (TB) of information, which is approximately 6,000 times the capacity of a CD- ROM, 830 times the capacity of a DVD, 160 times the capacity of single-layer Blu- ray-Discs, and about 8 times the capacity of standard computer hard drives as of 2007. The HVD also has a transfer rate of 1gigabyte/s
COMPONENTS Most holographic storage systems contain some components basic to the setup. These are:- a) Laser Beam b) Beam Splitters to split the Laser Beam c) Mirrors to direct the Laser Beam d) A liquid crystal Display panel (SLM) e) Lenses to focus the Laser Beam f) Recording Material g) CCD cameras
Holographic Versatile Discstructure 1. Green writing/reading laser (532 nm) 2. Red positioning/addressing laser (650 nm) 3. Hologram (data) 4. Polycarbonate layer 5. Photo polymeric layer (data- containing layer) 6. Distance layers 7. Dichroic layer (reflecting green light) 8. Aluminum reflective layer (reflecting red light) 9. Transparent base
How it Works Laser beams splits into 2 beams.o Beams works as object beam and Reference beam. To read the stored data, the media is illuminated by original reference beam. Thousands of Holograms can be stored in the same location by simply changing angle of reference. Multiple Data Recording is possible by Using Light at Different angles
Holographic Technology at Glance Advantages Associative memory capability Access All the Data in Few Microseconds Storage Capacity Increased Multiple Folds The HVD also has a transfer rate of 1 gigabit/s.
LIMITATIONS AND CHALLENGES It is very difficult to arrange all of those components like CCD camera , SLM arrays and beam steering devices. Needs good recordings sensitive material to allow high data transfer rate. If too many pages are stored in one crystal, the strength of each hologram gets diminished.
AdvantagesA) Pet flopComputingB) Data MiningC) FutureComputingSystem
CONCLUSION But even then the holographic way of storing data is still at However this the base stage and technology itself is It may offer high it may take another dazzling and aims todata transfer rate. couple of years for light up the desktop this technique to hit Experiences. desktop with a real life data storage solution.