PAPER PRESENTATION ON

1. PAPER PRESENTATION ON HOLOGRAPHIC DATA STORAGE By Ch.Sandhya, M.Arpitha, SaiSpurthi Institute of Tech.,Sathupalli

2. Why It is Emerging? • magnetic and conventional optical data storage technologies, where individual bits are stored as distinct magnetic or optical changes on the surface of a recording medium, are approaching physical limits beyond which individual bits may be too small or too difficult to store

3. How It Differs? • magnetic and optical data storage records information a bit at a time in a linear fashion, holographic storage is capable of recording and reading millions of bits in parallel, enabling data transfer rates greater than those attained by optical storage

4. Holographic data storage? • Holographic data storage is a potential replacement technology in the area of high-capacity data storage currently dominated by magnetic and conventional optical data storage. Magnetic and optical data storage devices rely on individual bits being stored as distinct magnetic or optical changes on the surface of the recording medium. Holographic data storage overcomes this limitation by recording information throughout the volume of the medium and is capable of recording multiple images in the same area utilizing light at different angles.

5. Types of Holographic Data Storage • Transmission Hologram • Can be used to store data • Uses coherent light • Reflection Hologram • The kind you find on credit cards • Uses white light

6. Creating Hologram

7. Data Storage Process 1.Holographic data storage 2.The first, called the object beam, contains the information to be stored; 3.The second, called the reference beam, is designed to be simple to reproduce

8. Inherent Parallelism With the inherent parallelism of its page wise storage and retrieval, a very large compound datarate can be reached by having a large number of relatively slow, and therefore low-cost, parallel channels. The data to be stored are imprinted onto the object beam with a pixilated input device called a spatial light modulator (SLM)

9. Holographic Recording Patterns “Stop and Go” “On the Fly” Conventional Holography Collinear Holography

10. Holographic Data storage system The image of the data page at the camera must be as close as possible to perfect. Any optical aberrations in the imaging system or miss focus of the detector array would spread energy from one pixel to its neighbors. Optical distortions (where pixels on a square grid at the SLM are not imaged to a square grid) or errors in magnification will move a pixel of the image off its intended receiver, and either of these problems (blur or shift) will introduce errors in the retrieved data

11. Hardware for holographic data storage • Holographic digital data storage testers • Coding and signal processing • Binary detection • Inter pixel interference • Error correction

12. holography is a volumetric technique, making its density proportional to one over the third power of the wavelength. In principle, laser beams can be moved with no mechanical components, allowing access times of the order of 10 ms, faster than any conventional disk drive will ever be able to randomly access data. As in other optical recording schemes, and in contrast to magnetic recording, the distances between the “head” and the media are very large, and media can be easily removable. In addition, holographic data storage has shown the capability of rapid parallel search through the stored data via associative retrieval.

13. Queries?

14. ThanQ! Ch.Sandhya & M.Arpitha