Fluorescent Multi-layer Disc (FMD) is a new data storage format implementing the concept of volumetric storage of information. FMD is an optical format, similar in size and appearance to regular CD-ROMs and DVDs.It may be possible to produce FMD discs with up to 140 GB of data.
The idea behind the disc is that traditional reflective surfaces prevent multiple layers because of diffraction. This however, will allow layers and layers of storage with fluorescent material instead of reflecting material.
1)Increased Disc Capacity
2)Quick Parallel Access and Retrieval of Information
4)Cost of production of FMD discs is relatively cheap.
TECHNOLOGY BEHIND FMD
The recording, reading and storing of the information is achieved through the use of fluorescent materials embedded in pits and groves in each of the layers. The fluorescent material emits radiation when excited by an external light source, which allows the information to be decoded by the changes in the intensity and colour of the emitted radiation. Principle of operation based on a phenomenon “photochromism”. An organic material called ‘‘stable photochrome’ is used as fluorescent material.With FMD/C technology, each storage layer is coated with a transparent fluorescent material rather than the reflective metallic layer of CD and DVD.
When the laser beam hits a mark on a layer, fluorescent light is emitted.The light emitted by fluorescent light is incoherent, unlike the coherent reflected light in current CD and DVD devices. Incoherent light is not affected by data pits or other marks in the media, and passes through adjacent data layers unaltered. In FMD/C devices, emitted light is filtered before it reaches the drive’s detector, which reduces the effect of stray light and interference – only data-conveying fluorescent light is detected.
Two types of technological process for manufacturing FMD:
SOME FEATURES OF FMD:
1)Implement the concept of volumetric storage of information.
2)FMD stores digital data in three dimensions FMD is a readable and re-writable disc.
3)Max data transfer rates are approximately 1GB/sec.
4)FMD is a transparent disc and consists of multiple data layers.
5)Data is recorded on multiple layers inside a disc.
6)Capacity of each data layer is 4.7GB.
7)Each data layer consists of pits & groves.
8)Pits are embedded with transparent fluorescent material.