2. What is Fiber optics
Fibre Optics = Fibre + Optics
Light Guided in Optical Fibre
Communication system with light as the carrier and fiber as communication medium.
Thin plastic glass
3. Structure Of Fibre Optics
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Core
Cladding
Buffer Coating
Higher Refractive Index
Lower Refractive Index
Mechanical Protection
4. Structure Of Fibre Optics
Core: Place in the centre of the fiber, this is
where the light will travel.
Cladding: outer optical material that reflects
the light back into the core.
Coating: Plastic buffer coating that protects
the fiber.
5. Detail of Fibre Optics Cables
• A thin and very fine strand of glass or plastic that carries light
transmissions over long distance.
• Fibre optics cables consist of one or more hair - thin filaments of
glass fiber wrapped in a protective jacket.
• They can conduct light pulse generated by lasers at transmission
rate as high as 30billion bits per second this is about 60times
greater than coaxial cables and 3000 times better than twisted pair
wires.
• Fibre optics also has a much lower data error rate than other media
and its harder to tap than electrical wire and cable.
• Fiber optic wire carries much more information than conventional
copper wire and is far less subject to electromagnetic interference.
Most telephone company long-distance lines are now fiber optic.
6. Classification of Fiber Optics
• SPEED: Fiber optic networks operate at high speeds - up into the
gigabits
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BANDWIDTH: large carrying capacity
• DISTANCE: Signals can be transmitted further without needing to
be "refreshed" or strengthened.
• RESISTANCE: Greater resistance to electromagnetic noise such as
radios, motors or other nearby cables
• MAINTENANCE: Fiber optic cables costs much less to maintain.
8. Types of Optical Fiber
• There are two types of Fiber Optics
cables:
1. Singe Mode Cable:
Singlemode fiber generally is usable up to about
100KM (62 miles) without a repeater.
Laser light transmitters normally are used to send
information over singlemode fiber, because high light
power is needed to reach long distances.
Used to transmit one signal per fiber (Single Mode
fibers are generally used for telephone and cable tv
applications.)
9. Types of Optical Fiber
2. Multi Mode Cable
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Used to transmit many signals per fiber. (Multi Mode fibers are
generally used for computer networks, lan applications).
Types Of Multi Mode Cables
1.In multimode step-index fiber
The density of the core remains constant from the center to the edges.
2. In multimode graded-index fiber,
Decreases the distortion of the signal through the cable.
12. Advantages of fiber Optics
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Higher bandwidth.
Less signal attenuation.
Immunity to electromagnetic interference.
Resistance to corrosive materials.
Light weight.
Greater immunity to tapping.
13. Disadvantages of Fiber Optics
• Installation and maintenance. Fiber-optic cable is a
relatively new technology. Its installation and maintenance
require expertise that is not yet available everywhere.
• Unidirectional light propagation. Propagation of light is
unidirectional. If we need bidirectional communication, two
fibers are needed.
• Cost. The cable and the interfaces are relatively more
expensive than those of other guided media. If the demand for
bandwidth is not high, often the use of optical fiber cannot be
justified.
