BLU-RAY DISC INTRODUCTION:- Blu-ray, also referred to as Blu-ray Disc (BD), is the name associated with a next generation optical disc format. It has the same physical proportions as standard DVDs and Compact disks, however offers over five times the storage capacity of conventional DVDs, holding up to 27 GB of data on a single-layer disc (that's more than 2 hrs of high definition video or about thirteen hrs of standard video) and up to 50 GB on a dual-layer disc. Current developments by Pioneer have pushed the storage potential to 500GB on a solitary disc by using 20 layers. Although present optical disc technologies such as DVD make use of a red laser to read and write data, the Blu-ray format uses a blue-violet laser in its place. The advantage of using a blue-violet laser (405 nm) is that it's got a shorter wavelength than a red laser (650 nm), which makes it feasible to focus the laser spot with even greater accuracy. This enables data to be packed more closely and stored in a reduced amount of space, so it's possible to fit more data on the disc. However, despite the different type of lasers used, Blu-ray products can easily be made backwards compatible with CDs and DVDs through the use of a BD/DVD/CD compatible optical pickup unit. Optical drives needed to move from using red to blue lasers, critical because the wavelength of an optical drive's laser light limits the size of the pit that can be read from the disc. In other words, the blue laser's smaller wavelength, narrower beam can be more finely focused on a smaller area than that of a red laser. Using blue laser light, several times more data can be stored on a single disk of the same physical size, and also transferred at considerably faster speed. BLU RAY TECHNOLOGY HISTORY: - WHO CREATED IT? in the next millennium, high definition video demands a new solution. History proved that a significant 5-10 x increase in storage capacity and the ability to play previous generation formats are key elements for a new format to succeed. This new format has arrived with the advent of Blu-ray Disc, the only format that offers a considerable increase in storage capacity with its 25 to 50 GB data capacity. This allows for the next big application of optical media: the distribution and recording of high definition video in the highest possible quality.In fact, no other format can offer the data capacity of Blu-ray Disc, and no other format will allow for the same high video quality and interactive features to create the ultimate user experience. As with DVD, the Blu-ray Disc format is based on the same, bare disc physical form factor, allowing for compatibility with CD and DVD. APPLICATION :- - High Definition Television Recording - High Definition Video Distribution - High Definition Camcorder Archiving - Mass Data Storage - Digital Asset Management and Professional Storage.