employed in the production of Blu-ray Disc is quite distinct and unique. An
optical pick-up technique is used in transmitting video, audio, or information
unto the BD layer. The Blu-ray Disc (BD) system uses blue light
and a high numerical aperture (NA) of 0.85. A cover layer thickness of 0.1 mm
is chosen to secure sufficient disk tilt
margin [Maxim, 2007].
The next part is the recording layer where the
information is written, stored and read. The recording layer works no
differently to a DVD. A single layered disc will be burnt with a laser that
burns at 4 to 11 mW. Burning the recording layer creates a pit were the
information is held; the laser burns the layer at 220oC [webelements,
2005]. BD layer is made of a mixture of four different elements. These are Silver
(Ag), Indium (In), Antimony (Sb) and Tellurium (Te).