CCNA RnS #10 - Fiber-optics Cable
CCNA RnS Article #10 – Fiber Optics Cable
Today in this article I am going to over the fiber Optic
cable components and data transmission concepts over it. Fiber optic cable uses
glass as the medium through which light passes this varying light over time
encodes 0s and 1s.
This fiber optic glass is not the same that we use for
commercial constructions but it’s a fiberglass. This allows long cables to hold
thin strings of flexible glass. Figure 1 shows the components of the fiber optic
cable – the outer 3 layers (Cable Jacket, Strengthening Fiber, and Coating) protect the inner 2 layers (Cladding & core). The inner layers the cladding and core build
an environment that allows light to travel through the core.
Figure 1: Fiber-optic Cable components
The light source at each end is called the optical
transmitter and it shines a light into the core. Cladding reflects the light back
to the core as it travels.
Figure 2: Multi-Mode Fiber
Figure 2 shows the multimode fiber cable operation where the
cable allows multiple angles of light to enter the core. Single-mode fiber uses
a smaller core and a laser-based transmitter is used to send the light at a
single angle – therefore it is called the single-mode fiber optic cable.
Figure 3: Single-Mode Fiber
Single-mode fiber has a smaller core size of 9 microns and
has a single light path. A smaller light path allows single-mode cable to cover
a much distance of up to 100 km.
Figure 4: Diameter SMF & MMF
|
Multi-mode Fiber |
Single-mode Fiber |
|
Carry multiple
light rays |
Single light ray |
|
Low cost
compared to SMF |
Expensive |
|
Distance - up
to 2km |
Distance up to
100km |
|
Core – 50 microns |
Core – 9 microns |
Another reason customers prefer fiber over UTP is resistance to EMI interference and there is no faint single possibility outside the cable. So for secure environments such as manufacturing plants fiber optic cable is preferred. Hope you find this informative.
