3d optical data storage ppt
- 1. 3D OPTICAL DATA STORAGE. DONE BY :- MUHAMMED OWAIZ. ‘X’ STD
- 2. .C0NTENTS. INTRODUCTION. OVERVIEW. MEDIA DESIGN. MEDIA FORM FACTOR. MEDIA MANUFACTURING. COMMERCIAL DEVELOPMENT. BASIC COMPONENT. ADVANTAGES AND DISADVANTAGES. CONCLUSION.
- 3. .INTRODUCTION. 3D optical data storage is the term given to any form of optical data storage in which information can be recorded and/or read with three dimensional resolution ( as opposed to the two dimensional resolution afforded, for example :- CD. This innovation has the potential to provide byte-level mass storage on DVD-sized disks. Data recording and read back are achieved by focusing lasers within the medium. No commercial product based on 3D optical data storage has yet arrived on the mass market, although several companies are actively developing the technology and claim that it may become available soon.
- 4. .OVERVIEW. Current optical media, such data storage as the CD and DVD store data as a series of reflective marks on an internal surface of a disc. In order to increase storage capacity, it is possible for discs to hold two or even more of these data layers, but their number is severely limited since the addressing laser interacts with every layer that it passes through on the way to and from the addressed layer. As an example, a prototypical 3D optical data storage system may use a disc that looks much like a transparent DVD. The disc contains many layers of information, each at a different depth in the media and each consisting of a DVD-like spiral track.
- 5. .MEDIA DESIGN. The active part of 3D optical storage media is usually an organic polymer either doped or grafted with the photo chemically active species. Alternatively, crystalline and sol-gel materials have been used.
- 6. .MEDIA FORM FACTOR. Media for 3D optical data storage have been suggested in several form factors: disk, card and crystal. DISC:- A disc media offers a progression from CD/DVD, and allows reading and writing to be carried out by the familiar spinning disc method. CARD:- A credit card form factor media is attractive from the point of view of portability and convenience, but would be of a lower capacity than a disc. CRYSTAL,CUBE AND SPHERE:-Several science fiction writers have suggested small solids that store massive amounts of information, and at least in principle this could be achieved with 5D optical data storage.
- 7. .MEDIA MANUFACTURING. The simplest method of manufacturing – the molding of a disk in one piece – is a possibility for some systems. A more complex method of media manufacturing is for the media to be constructed layer by layer. This is required if the data is to be physically created during manufacture. However, layer-by-layer construction need not mean the sandwiching of many layers together.
- 8. .DRIVE DESIGN. A drive designed to read and write to 3D optical data storage media may have a lot in common with CD/DVD drives, particularly if the form factor and data structure of the media is similar to that of CD or DVD. However, there are a number of notable differences that must be taken into account when designing such a drive. LASER. VARIABLE SPHERICALABERRATION CORRECTION. OPTICAL SYSTEM. DETECTION. DATA TRACKING.
- 9. .COMMERCIAL DEVELOPMENT. In addition to the academic research, several companies have been set up to commercialize 3D optical data storage and some large corporations have also shown an interest in the technology. However, it is not yet clear whether the technology will succeed in the market in the presence of competition from other quarters such as hard drives, flash storage, and holographic storage. Examples of 3D optical data storage media. Top row – written call/recall media; Mempile media. Middle row – FMD; D-Data DMD and drive. Bottom row- landauer media ; Microholeas media in action
- 10. .BASIC COMPONENTS. Optical data storage system requires certain important materials for its data storage and retrieval processes. The important components required for the optical data storage are:- Laser Lens and Mirrors Spatial Light Modulators(SLM) Photosensitive materials Charge Coupled Devices(CCD) Phase masks for encryption
- 11. .LASER. Laser is a device for the generation of coherent, nearly monochromatic and highly directional electromagnetic radiation emitted, somewhere in the range from sub- millimeter through ultraviolet and x-ray wavelengths. More than two hundred types of lasers have been fabricated which range in power , size , performance, use and cost.
- 12. .LENS AND MIRROR. Mirrors are used to reflect laser beams to the desired direction. Lenses are usually used to converge the laser to a point. A special type lens is used in the case of optical recording called the Fourier lens. The lens has the property of obtaining the Fourier transform and the inverse transform system is described below: Lens as a Fourier transform system.
- 13. .SPATIAL LIGHT MODULATER. SLM is an optical device that is used to convert the real image or data into a single beam of light that will intersect with the reference beam during recording. It basically consists of an array of pixels which are usually microscopic shutters or LCD displays . These can be controlled by a computer. The computers sends binary data to the SLM.
- 14. .PHOTO SENSITIVE MATERIALS. PHOTOREFRACTIVE CRYSTALS. PHOTOPOLYMERS.
- 15. . PHOTO REFLECTIVE CRYSTALS. There are two main types of materials used for the holographic storage medium. These are photo refractive crystals and photo polymers. The recording medium usually used is a photo refractive crystals such as LiNbO3 or BaTiO3 that has certain optical characteristics. These characteristics include high diffraction efficiency, high resolution, permanent storage until erasure, and fast erasure on the application of external stimulus such as UV light. Photo refractive crystals are suitable for random access memory with periodic refreshing of data, and can be erased and written to many times.
- 16. .PHOTO POLYMER. Photopolymers have been developed that can also be used as a holographic storage medium. Typically the thickness of the photopolymers is much less then the thickness of photo reflective crystals because the photopolymers are limited by mechanical stability and optical quality. Example :- A photopolymer is a 100m thickness, which is greater than DVD-ROM by a factor of two. Stored holograms are permanent and degrade over time or by read out of the hologram, so photopolymers are suited for read only memory(ROM).
- 17. .CHARGE COUPLED DEVICES(CCD). The charge-coupled device is, by far the most common mechanism for converting optical images into electrical signals. CCD’s are silicon devices, which contain an array of potential wells created through a series of column, implants( for vertical confinement). Each pixel is typically 15-30µm square. Current CCD’s have formats or resolution better than 2048*2048 pixels, with a size of about 25mm square.
- 18. .PHASE MASK FOR ENCRYPTION. There is a wide spread interest in the development of encryption systems, which operate in the optical domain. The advantages inherent in the optical approach to encryption ,Such as a high space-bandwidth product, the difficulty of accessing, coping or falsification and the possibility of Including biometrics are widely recognized. In an encryption system, we wish to encode information in such a fashion that even if it is viewed or copied only the application of the correct key will reveal the original information.
- 19. .ADVANTAGES. Durability:- with proper care, optical media can last a long time, depending of what kind of optical media you choose. Great for archiving:-several forms of optical media are written once read many, which means that when data is written to them, they cannot be reused. This is of excellent for archiving because data is preserved permanently with no possibility of being overwritten. Transportability:-optical media are widely used in other platforms, including the PC. For ex:-data written to them on a DVD-RAM can be read on a PC or any other system with an optical device and the same file system. Random access:- optical media provide the capability to pinpoint a particular piece of data stored on it, independent of the other data on the volume or the order in which that data was stored on the volume .
- 20. .DISADVANTAGES. Reusable:- the write-once read-many(WORM) characteristic of some optical media makes it excellent for archiving, but it also prevents you from being able to use that media again. Writing time:- the server uses software compression to write compressed data to your optical media. This process takes considerable processing unit resources and may increase the time needed to write and restore that data.
- 21. .CONCLUSION. this presentation shows that a light field in such a structure can be localized in a sub wavelength-size area, suggesting a new way of arranging three-dimensional optical-memory devices. And this presentation was really fun cuz I had to make a presentation on exactly the way I’m presenting it in the form CD an optical storage device.