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Researchers at General Electric claim to have made a key breakthrough in optical data storage that could lead to commercial discs holding the equivalent of 100 DVDs within three years. The new technology is based on the physics of holograms, which enable information to be packed far more densely than with established recording formats. A new device will be needed to play these discs but this will be compatible with established formats like CDs, DVDs and Blu-ray discs, say the US-based team.

Invented over 50 years ago, holograms are now widely deployed as authentication tags, and can be found everywhere from credit cards and passports to cosmetics and pharmaceuticals. These futuristic surfaces can be generated in photosensitive materials by applying two coherent light beams: an “object” beam carrying information about a material’s structure; and a reference beam that records the desired pattern on the hologram. The resulting 3D interference pattern is usually stored as changes in refractive index of the recording material, which can be viewed when the material is illuminated by daylight.

Source: http://physicsworld.com/cws/article/news/39565