Blu-ray Technology

Yes, it is ray not the blue-ray. The letter ‘e’ was intentionally avoided to make it suitable for trademarking. And yes, the Blu-ray is more advanced and better than a DVD. Every one was so excited when DVDs came into existence in 1997 which made it possible playing digital audio/video even in our houses. Now, people are talking about the new technology which is even superior to DVDs that came into existence in 2006.

After VCR’s and DVDs, advances in technology brought us Blu-ray technology. The name blu-ray is derived from the fact that a blue (actually blue-violet) laser is used for reading and writing Blu disc.ray technology is not an achievement of any single company. A group of prominent companies like Apple, Dell, Sony, Sun Microsystems etc formed ray Disc Association which developed this technology.

Blu-ray discs are superior to DVDs in the following factors:

(a) More storage capacity A single-sided standard 12 cm DVD can store 4.7 GB of data whereas the same size single layer ray disc can store 25 GB of data which is almost five times greater than a DVD. A double layer ray disc can store 50 GB of data. Similar to DVDs we can get mini size ray discs also with the size of 8 cm. This mini disc with single layer capacity can store 7.8 GB and dual layer capacity can store 15.6 GB.
(b) Higher data transfer rate of 36 Mbps and,
(c) Audio and video are played with more clarity compared to DVD.

The following are the factors which are responsible to embed more data into a ray disc:

(a) Contrary to DVDs which depend on red lasers operating at 650 nm for reading and writing data, Blu-ray discs depend on blue laser that operates at 405 nm. As the ray technology is using the short wavelength laser compared to DVD, it can embed more data into the disc which has the same size of a DVD.
(b) The thickness of cover layer was decreased.
(c) Numerical aperture was increased to 0.85.

Different formats of ray disc:

(a) BD-R: Recordable format for HD video recording and PC data storage.
(b) BD-ROM: Read only format for pre-recorded contents like high definition movies, games.
(c) BD-RW: Rewritable format for PC data storage.
(d) BD-RE: Rewritable format for HD video recording and PC data storage.