Optical data storage
Optical storage is the storage of data on an optically readable medium. Data is recorded by making marks in a pattern that can be read back with the aid of light, usually a beam of laser light precisely focused on a spinning disk.
An older example that does not require the use of computers is microform. Optical storage differs from other data storage techniques that make use of other technologies such as magnetism or semiconductors. Optical storage can range from a single drive reading a single CD-ROM to multiple drives reading multiple disks such as an optical jukebox.
This display shows double-layer recordable Blu-ray Discs (BD-R) manufactured by Panasonic. Each double layer disk has a capacity of 50GB. The Blu-ray Disc is a digital optical disc data storage format. Originally designed to supersede the DVD format, it is capable of storing high-definition videos. The name ‘Blu-ray’ refers to the blue laser (specifically, a violet laser) used to read the disc, which allows information to be stored at a greater density than is possible with the longer-wavelength red laser used for DVDs.