What is a Blu-ray Disc?

Blu-ray Disc (official abbreviation BD) is an optical disc storage medium designed to supersede the DVD format. The standard physical medium is a 12 cm plastic optical disc, the same size as DVDs and CDs. Blu-ray Discs contain 25 GB per layer, with dual layer discs (50 GB) the norm for feature-length video discs and additional layers possible in the future.

The first Blu-ray Disc prototypes were unveiled in October 2000, and the first prototype player was released in April 2003 in Japan. After that, it continued to be developed until its official release in June 2006.
The name Blu-ray Disc refers to the blue laser used to read the disc, which allows information to be stored at a greater density than is possible with the longer-wavelength red laser used for DVDs.

Blu-ray Disc was developed by the Blu-ray Disc Association, a group representing makers of consumer electronics, computer hardware, and motion pictures. As of June 2009^[update], more than 1,500 Blu-ray Disc titles were available in Australia and the United Kingdom, with 2,500 in the United States and Canada. In Japan, as of July 2010^[update], more than 3,300 titles have been released.


During the high definition optical disc format war, Blu-ray Disc competed with the HD DVD format. Toshiba, the main company that supported HD DVD, conceded in February 2008, releasing their own Blu-ray Disc player in late 2009.

In 1992, the Japanese inventor Shuji Nakamura invented the first efficient blue LED, and four years later, the first blue laser. Nakamura used the material deposited on sapphire substrate, although the number of defects remained very high (10^6-10^10/cm2). The presence of defects in the structure of the laser made it difficult in a very important way to build a high-powered laser. In the early 90s at the Institute of High Pressure Physics PAS in Warsaw, under the leadership of Dr. Sylwester Porowski [2] was developed technology of gallium nitride crystals with very high structural quality - number of defects did not exceed 100/cm2 it was at least 10 000 times less than the best material deposition on sapphire. In 1999, Shuji Nakamura invented the crystal used to investigate the effects of defects on the properties of lasers. Lasers built on Polish crystal has repeatedly proved to be better than previously constructed, both in terms of life span and performance. The lifetime of the power of 30 mW has increased 10-fold (from 300 to 3 000 hours), and the yield more than double. A further comprehensive development of technologies taking off from sapphire substrates led to the launch of the first mass production of the device, which uses blue lasers. After 10 years of controlled production in Japan, blue laser power of 60mW was achieved. Nakamura's technological successes have created the basis for a new field of lighting and progress in the electronics industry. Nakamura was awarded the 2006 Millennium Technology Prize Award, often called the Nobel Prize of technological achievements.