Blu-ray, which is also commonly known as Blu-ray Disc, is the name of the next-generation optical disc format. It was jointly developed by the Blu-ray Disc Association, which is a group of the world's leading consumer electronics, personal computer and media organizations. This new format was developed to enable recording, rewriting and playback of high-definition video, as well as storing enormous amounts of data.
The name Blu-ray was derived from the blue-violet laser that is used to read and write on this type of disc. Because of the shorter wavelength, a lot more data can be stored on these discs than using the common DVD format. Blu-ray offers more than five times the storage capacity of the traditional DVDs, and can hold as much as 25GB on a single-layer disc and 50GB on a dual-layer disc.
The extra storage capacity means there will be plenty of room for additional content, special features, and greater video and audio quality. This combined with a new interactivity layer adopted by Blu-ray will bring the menus, graphics and special features to a completely new level. For instance, you will be able to bring up the menu as an overlay without stopping your movie. The advanced interactivity combined with the networking features of Blu-ray will also allow content producers to support new innovative features such as downloading extras, updating content via the internet, and watching live broadcasts of special events.
Each Blu-ray disc is about the same thickness as a regular DVD. However, the two types of discs store the data quite differently. With a DVD, the data is sandwiched between two polycarbonate layers, which can cause a problem referred to as birefringence. This is where the substrate layer refracts the laser light into two separate beams. If the beam is split too widely, the disc cannot be read. Also, if the DVD surface is not exactly perpendicular to the beam, it can lead to a problem known as disc tilt, in which the laser beam is distorted. All of these issues can cause the DVD disc to become unusable and the data on them irretrievable.
The Blu-ray disc overcomes these DVD-reading issues by placing the data on top of a 1.1-mm-thick polycarbonate layer. By having the data on top, it prevents the birefringence issue and therefore prevents the readability problems. With the recording layer sitting closer to the lens, the problem of disc tilt is virtually eliminated. Additionally, a hard coating is placed on the outside of the disc to further protect it from scratches and fingerprints, etc.
The design of Blu-ray discs actually saves money on the manufacturing costs. Traditional DVDs are built by injection molding of two discs between where the recording layer is sandwiched. This process must be done very carefully to prevent birefringence. However, Blu-ray discs only do the injection-molding process on a single disc, which reduces the cost. That savings balances out against the cost of adding a protective layer, so the end price is no more than the price of a regular DVD.
Many of the world’s leading consumer electronics, personal computer, recording media, video game and music companies, support Blu-ray technology. It also has broad support from the major movie studios as a successor to today's DVD format. Most major movie studios have already announced titles for Blu-ray. Many studios have also announced that they will be releasing new feature films on Blu-ray Disc, as well as a continuous slate of new catalog titles every month.
As with any new technologies, Blu-ray equipment is of course more expensive than the traditional DVD players are. However, prices will drop as the format gains popularity and the technology becomes more commonplace. Even when the new video standard begins to replace the current technologies, you will not have to throw away all of their old DVDs as the Blu-ray players will be backwards compatible. They will however need to think about investing in a new player to take advantage of the many benefits that Blu-ray has to offer.