Principles of light, Fiber material, Wavelength – Elenco Fiber Optics Voice and Data Kit User Manual
Page 9: Figure 2a, Plastic optical cable core cladding jacket
PRINCIPLES OF LIGHT
WAVELENGTH
SECTION B
Plastic Optical Cable
Core
Cladding
Jacket
-8-
FIBER MATERIAL
There are many materials that can be used to transmit light. The two most
popular optical fibers are glass, which has the best optical characteristics,
and plastic. Plastic is less expensive and does not break easily. This kit
uses a plastic optical cable similar to the one shown.
Light occupies only a small portion of the
electromagnetic spectrum shown in Figure 2A. The
equation
λ = c/f is used to convert frequency to
wavelength, where
λ = wavelength, c = speed of
light, and F = Frequency of the light wave.
Note that in Figure 2A, the visible range of light is
approximately 380 x 10
-9
meters (violet) to 750 x
10
-9
meters (red). When using plastic as the fiber
optic cable medium, the best results occur around
660 x 10
-9
(orange-red).
Light also can be thought of as little bundles of
energy being rapidly transmitted. These discrete
groups of energy are called photons, and the
amount of energy present in each photon is
dependent on the frequency at which they are
transmitted. Higher frequencies produce more
energy than lower frequencies of light. The equation
for the amount of energy in each photon is E = h
ƒ.
Where E = energy in joules, h is Planck’s constant
(6.63 x 10
-34
joules-seconds), and
ƒ is the frequency
in hertz.
It is important to remember that light can be
explained on a wave or a photon energy packet
when investigating the properties of fiber optics.
0
10
10
2
10
3
10
4
10
5
10
6
10
7
10
8
10
9
10
10
10
11
10
12
10
13
10
14
10
15
10
16
10
17
10
18
10
19
10
20
10
21
10
22
Sonic
Sound
AM Radio
Shortwave Radio
Television & FM Radio
Radar
Infrared Light
Ultraviolet Ray
X-Ray
Gamma Ray
Cosmic Ray
Frequency
(Hz)
Visible Light
Wavelength
(nm)
Ultraviolet
Violet
Blue
Green
Orange
Red
Infrared
400
455
490
550
620
750
800
Figure 2A