Just for you guys

1. Optical Fiber
By: Irfan Anjum
Subject: Data Communication and
Computer Network
Semester: 6th Bachelor of Electrical
Technology
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2. What is Optical Fiber?
• An Optical fiber is a flexible, transparent fiber made of high
quality glass (silica) or plastic, slightly thicker than a human hair.
• It either functions as a waveguide or light pipe that transmits
light between two ends of the fiber or fiber cable.
• Optical fibers are widely used in fiber-optic communications,
which permits transmission over longer distances and at
higher bandwidths (data rates) than other forms of
communication
• Fibers are used instead of metal wires because signals travel
along them with less loss and are also safe to electromagnetic
interference.
• The field of applied science and engineering concerned with the
design and application of optical fibers is known as fiber optics.
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3. History of Fiber Optics
• Fiber optics is not really a new
technology, its fairly old.
• Guiding of light by refraction, the
principle that makes fiber optics
possible, was first demonstrated
by Daniel Colladon and Jacques
Babinet in Paris in the early 1840s
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4. Uses of Optical Fiber
• Fiber optic can accommodate variety of needs.
• It can be used in Communication, fiber optic sensors,
illumination, medical.
• And also in other places where bright light needs to be shone
on a target without a clear line-of-sight path.
• Used in building to route sunlight from the roof to other parts
of the building.
• And many more usages but we will only discuss use of optical
fiber in communication here.
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5. In Communication
• Optical fiber can be used as a medium for telecommunication
and computer networking because it is flexible and can be bundled
as cables.
• It is especially advantageous for long-distance communications,
because light propagates through the fiber with little attenuation
compared to electrical cables.
• The per-channel light signals propagating in the fiber have been
modulated at rates as high as 111 gigabits per second (Gbit/s)
by NTT, although 10 or 40 Gbit/s is typical.
• In June 2013, researchers demonstrated transmission of 400 Gbit/s
over a single channel.
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6. Continued…
• Each fiber can carry many independent channels, each using a
different wavelength of light.
• As of 2011 the record for bandwidth on a single core was 101
Tbit/sec (370 channels at 273 Gbit/sec each).
• The record for a multi-core fibre as of January 2013 was 1.05
petabits per second
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7. Benefits of Optical Fiber
• For short distance application, such as a network in an office building, fiber-optic
cabling can save space in cable ducts. This is because a single fiber can carry
much more data than electrical cables such as standard category 5 Ethernet
cabling, which typically runs at 100 Mbit/s or 1 Gbit/s speeds.
• Fiber is also immune to electrical interference; there is no cross-talk between
signals in different cables, and no pickup of environmental noise.
• Non-armored fiber cables do not conduct electricity, which makes fiber a good
solution for protecting communications equipment in high
voltage environments, such as power generation facilities, or metal
communication structures prone to lightning strikes.
• They can also be used in environments where explosive fumes are present,
without danger of ignition.
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8. Structure of Optical Fiber
• Optical fiber is comprised of a light carrying core
surrounded by a cladding which traps the light in the core
by the principle of total internal reflection.
• Most optical fibers are made of glass, although some are
made of plastic.
• The core and cladding are usually fused silica glass which is
covered by a plastic coating called the buffer or primary
buffer coating which protects the glass fiber from physical
damage and moisture.
• There are some all plastic fibers used for specific
applications.
• Glass optical fibers are the most common type used in
communication applications.
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9. Modes of propagation
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 Single mode – there is only one path for light to take down the cable
 Multimode – if there is more than one path
Cladding
Cladding

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Structure of single-mode fiber
 1. Core: 8 µm diameter
 2. Cladding: 125 µm dia.
 3. Buffer: 250 µm dia.
 4. Jacket: 400 µm dia.

11. Loss in Optical Fiber
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Losses vary greatly depending upon the type of
fiber
Plastic fiber may have losses of several hundred dB
per kilometer
Graded-index multimode glass fiber has a loss of
about 2–4 dB
per kilometer
Single-mode fiber has a loss of 0.4 dB/km or less

12. What is it made of?
• Silica
• Plastic
• Fluoride
• Phosphates
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13. Optical fiber cables
• In practical fibers, the cladding is usually coated with a
tough resin buffer layer, which may be further surrounded by
a jacket layer, usually glass. These layers add strength to the fiber
but do not contribute to its optical wave guide properties
• Modern cables come in a wide variety of sheathings and armor,
designed for applications such as direct burial in trenches, high
voltage isolation submarine installation, and insertion in paved
streets.
• Fiber cable can be very flexible, but traditional fiber's loss increases
greatly if the fiber is bent with a radius smaller than around 30 mm.
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14. Types of Optical fiber cable
• Loose Tube Cable
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Coated Fiber
Outer Jacket
Steel Tape Armor
Inner Jacket
Aramid Strength Member
Binder
Interstitial Filling
Central Member
(Steel Wire or Dielectric)
Interstitial Filling
Loose Tube Cable

15. Continued…
• Tight buffered Cable
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Glass Fiber
Thermoplastic
Overcoating or
Buffer
PVC Jacket (Non-Plenum) or
Fluoride Co-Polymer Jacket
(Plenum)
Fiber Coating
Aramid Strength
Member
Tight-buffered Cable

16. Types of Optical fiber cable
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17. 17
Fiber Connectors

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19. Did you know?
• A small optical fiber can carry more data than a large copper
cable.
• It is a unidirectional technology.
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20. System
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Electrical
Connector Electrical
Connector
Transceiver
Transceiver
Fiber Optic Cable
Optical
Connector
Optical
Connector
Optical
Port
Optical
Port
A failure anywhere along this link will cause the entire link to fail

21. Continued…
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22. Advantages of Optical Fiber over Conventional Copper System
• Broad Bandwidth
– Broadband communication is very much possible over fiber optics which
means that audio signal, video signal, microwave signal, text and data from
computers It is possible to transmit around 3,000,000 full-duplex voice or
90,000 TV channels over one optical fiber.
• Electrical Insulator
– Optical fibers are made and drawn from silica glass which is nonconductor of
electricity and so there are no ground loops and leakage of any type of
current. Optical fibers are thus laid down along with high voltage cables on
the electricity poles due to its electrical insulator behavior.
• Immunity to Electromagnetic Interference
– The optical fiber is electrically non-conductive, so it does not act as an
antenna to pick up electromagnetic signals which may be present nearby
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23. Continued…
• Low attenuation loss over long distances
– There are various optical windows in the optical fiber cable at which
the attenuation loss is found to be comparatively low and so
transmitter and receiver devices are developed and used in these low
attenuation region. Due to low attenuation of 0.2dB/km in optical
fiber cables, it is possible to achieve long distance communication
efficiently over information capacity rate of 1 Tbit/s.
• Lack of costly metal conductor
– The use of optical fibers do not require the huge amounts of copper
conductor used in conventional cable systems. In recent times, this
copper has become a target for widespread metal theft due its value
on the scrap market.
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24. Optical Fiber in Sea
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25. Any QUESTIONS ?
Heartiest thanks
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