High-definition optical disc format war April 2008, the firm estimated a total of 10.5 million Blu-ray households, including Blu-ray consoles and Blu-ray-enabled PlayStation 3s. High-definition optical disc format war The high-definition optical disc format war was between the Blu-ray and HD DVD optical disc standards for storing high-definition video and audio; it took place between 2006 and 2008 and was won by Blu-ray Disc. The two formats emerged between 2000 and 2003 and attracted both the mutual and exclusive support of major consumer electronics manufacturers, personal computer manufacturers, television and movie producers and distributors, and software developers. Blu-ray and HD DVD players became commercially available
Optical medium Optical medium An optical medium is material through which electromagnetic waves propagate. It is a form of transmission medium. The permittivity and permeability of the medium define how electromagnetic waves propagate in it. The medium has an "intrinsic impedance", given by where formula_2 and formula_3 are the electric field and magnetic field, respectively. In a region with no electrical conductivity, the expression simplifies to: For example, in free space the intrinsic impedance is called the characteristic impedance of vacuum, denoted "Z", and Waves propagate through a medium with velocity formula_6, where formula_7 is the frequency and formula_8 is the wavelength