LG BH100 Training Manual page 7

OVERVIEW
Wave patterns have three characteristics,
Amplitude, Frequency, and wavelength decreases.
Wavelength is a direct correlation with size. Once
wavelengths enter the light spectrum, higher
frequencies equal lower wavelength. Therefore
Red light has the largest wavelength in the visible
spectrum and Violet has the smallest wavelength.
CD technology uses what is technically an Infrared
(785nm) laser. DVD technology, holding about 7 times
more data than CD, uses what is considered a Ruby Red
(660nm) laser. The "Next-Gen" DVD technologies use a
new Blue-Violet (405nm) laser. This new "Blue" laser
has a much smaller wavelength, and in turn a smaller
size. As a result, this Blue laser can read "smaller" data.
This is the principle behind increasing capacity for the
Next-Gen formats.
The Next-Gen technology main discussed in this manual
is Blu-ray Disc (BD). By using the Blue laser's smaller
spot size (0.58µm vs. DVD's 1.32µm) and smaller data
areas on the disc (Track pitch of 0.32 µm vs. DVD's
0.74µm and Minimum pit length of 0.149µm vs. DVD's
0.74µm), BD technology allows for 25GB of data per
layer on a disc.
7
BH100 Blu-ray Player Overview