Blue Ray
...5: Why Blu-ray?
6: Store!
7: Get RID of it
8: The recording technology
9: Groovy!
10: Land Ho!
11: Those who not like it
12: MPEG
13: Basic Blu-ray Disc Characteristics
14: Main Specifications
15: Conclusion
1:A little science first
As we all know, CD players and recorders read and write the CD’s with the aid of a laser. Laser is short for: Light Amplification by Stimulated Emission of Radiation.
In a nutshell this means that high emitted energy gives radiation in the form of light, sort of like a lightbulb does. However laser light is very different than your average lightbulb. Laser comes in a straight direct beam and in only one wavelength (only red, only green, only blue etc). This wavelength is measured in nanometers and science uses the Greek letter Lamda () for this.
Because a laser is a very tiny and direct beam it is perfect to reflect the data written on a cd, because the data is long (over 3 miles!) but it is very small (about 5 microns).
The laser sends a beam towards the cd data and the beam gets reflected or not, thus resulting in high or low digital signal. To put it simple: If the reflected beam gets picked up by the receptor, it’s a 1 ,if not.. it’s a 0.
If you write data on a cd, the real laser power kicks in. It actually heats up a certain part of the cdrom surface, thus creating a physical 0 or 1 on the cdrom, which can later be read by your cd player.
The smaller the wavelength of a laser is, the smaller the beam can be. If the beam is smaller .. it can also read/write the same data using a smaller width (less than 1 micron!). So, on the same amount of surface, a laser with a smaller wavelength can read/write far more data on that surface than a laser with a bigger wavelength! And that’s what Blu-Ray is! A laser with a smaller wavelength. Blue.
2:Blue?
Blu-Ray uses a blue laser....
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