Optical digital versatile disk

Optical memory devices such as compact disks (CDs) and digital versatile disks (DVDs) are becoming essential items of audio and visual media as well as of external computer memory media. In these devices, a laser beamis used to record and read information. Because the laser spot can be focused to within a 1 fxm scale, optical memory can access higher density and capacity than conventional magnetic memories can. 

Finally, Part IV reviews miscellaneous technical developments that do not fit neatly into the scheme of the preceding parts. These concern, in particular, the application of polymers in the field of optical memories, treated in Chapter 12, which refers also to currently important data storage systems (compact disks, digital versatile disks, and blue-ray disks). Moreover, the application potential of polymers in the fields of photosensors and photocatalysts is outlined in Chapters 13 and 14, respectively. 

Digital Versatile Disc (DVD) Optical storage disk that can hold fi-om 4.7 to 8.7 gigabytes of data. 

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