Introduction to Optical Fibre Presentation

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Presented byosama naseem

• OPTICAL fIBRE AND ITS ADVANTAGES

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Table of contents

• What is OPTICAL FIBRE?
• Evolution of OPTICAL FIBRE
• Components of OPTICAL FIBRE
• Total Internal Reflection
• How OPTICAL FIBRE works?
• Types of OPTICAL FIBRE
• Advantages and Disadvantages of OPTICAL FIBRE

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What is OPTICAL FIBRE?

• Fiber optics (optical fibers) are long, thin
  strands of very pure glass about the diameter of
  a human hair.
• They are arranged in bundles called optical
  cables and used to transmit light signals over
  long distances.

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EVOLUTION OF OPTICAL FIBRE

• 1880 Alexander Graham Bell
• 1930 Patents on tubing
• 1950 patents for two layer glass wave guide
• 1960 Laser first used as alight source
• 1965 High loss of light discovered
• 1970 Refining of manufacturing process
• 1980 OPTICAL FIBRE becomes backbone of long
  distance telephone networks

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COMPONENTS OF OPTICAL FIBRE

• CORE thin glass centre where the light
  travels.
• CLADDING outer optical material that surrounds
  the core.
• BUFFER COATING plastic coating that protects
  the fibre.

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DIAGRAM
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TOTAL INTERNAL REFLECTION (TIR)

• To understand how optical fibre works we have
  to understand the concept of TIR.
• When the angle of incidence becomes larger than
  the critical angle, no refraction occur. The
  entire light is reflected back into the denser
  medium. This is known as TOTAL INTERNAL
  REFLECTION.

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DIAGRAM OF TIR
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HOW OPTICAL FIBRE WORKS?

• Light that enters the core at one end of the
  optical fibre goes straight and hits the inner
  wall(cladding) of fibre optics. The angle of
  incidence with cladding is greater than the
  critical angle, light is totally reflected into
  the fibre optics until it hits the inner wall
  again, and so on.
• As explained above, this phenomena is TOTAL
  INTERNAL REFLECTION.

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DIAGRAM
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TYPES OF OPTICAL FIBRE

• There are two basic types of optical fibre.
• SINGLE MODE FIBRE
• MULTI-MODE FIBRE

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SINGLE MODE FIBRE

• Single mode fiber is optical fiber that is
  designed for the transmission of a single ray or
  mode of light as a carrier .
• It is used for long-distance signal transmission.
• This fibre is used in telecom and CAT V networks.

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DIAGRAM
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MULTI-MODE FIBRE

• Each optical fibre in a multi-mode cable is about
  10 times thicker than fibre optics used in a
  single mode cable. This means light beams can
  travel through the core by following different
  paths,hence the name multi-mode.
• Multi-mode cable can send information only over
  relatively short distances and are used to link
  computer networks together.

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DIAGRAM
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ADVANTAGES

•  Bandwidth - Fibre optic cables have a much
  greater bandwidth than copper cables. The amount
  of information that can be transmitted per unit
  time of fibre over other transmission media is
  its most significant advantage. 
•   Low Power Loss - An optical fibre offers low
  power loss. In comparison to copper in a
  network, the longest recommended copper distance
  is 100m while with fibre, it is 2000m. 

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• Interference - Fibre optic cables are immune to
  electromagnetic interference.  It can also be run
  in electrically noisy environments without
  concern as electrical noise will not affect
  fibre. 
•  Size - In comparison to copper, a fibre optic
  cable has nearly 4.5 times as much capacity as
  the wire cable has and a cross sectional area
  that is 30 times less. 
•  Weight - Fibre optic cables are much thinner and
  lighter than metal wires.  They also occupy less
  space with cables of the same information
  capacity.  Lighter weight makes fibre easier to
  install.

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• Safety - Since the fibre is a dielectric, it does
  not present a spark hazard. 
• Security - Optical fibers are difficult to
  tap. fibre is the most secure medium available
  for carrying sensitive data. 
• Flexibility - An optical fibre has greater
  tensile strength than copper or steel fibers of
  the same diameter.  It is flexible, bends easily
  and resists most corrosive elements that attack
  copper cable. 

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DISADVANTAGES

• Cost -  Cables are expensive to install but last
  longer than copper cables.
• Transmission - Transmission on optical fiber
  requires repeating at distance intervals. 

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• Fragile -  Fibers can be broken or have
  transmission loses when wrapped around curves of
  only a few centimeters radius.  However by
  encasing fibers in a plastic sheath, it is
  difficult to bend the cable into a small enough
  radius to break the fiber.

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• Thank You
• Any Question?