3. What is Optical Fiber ?
• Fiber optics (optical fibers) are long, thin strands of very pure glass
about the diameter of a human hair & arranged in bundles
called optical cables and used to transmit light signals over long
distances
• It either functions as a waveguide or light pipe that transmits light
between two ends of the 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
4. 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 and Jacques Babinet in
Paris in the early 1840s.
5. Uses of Optical Fiber
• Fiber optic can accommodate variety of needs.
• It can be used in Communication, fiber optic sensors, illumination &
medical.
• Fiber can be used under sea communication.
• Fiber are used in public utility organizations like railways & TV
Transmissions etc.
• Military and Space Applications With the high level of data security
required in military and aerospace applications, fiber optic cables offer
the ideal solution for data transmission in these areas.
6. Uses of Optical Fiber
• Computer Networking between computers in a single building or across
nearby structures is made easier and faster with the use of fiber optic
cables
• Telephone Calling telephones within or outside the country has never
been so easy. With the use of fiber optic communications, wecan
connect faster and have clear without any lag on either side.
• Used to connect users and servers in a variety of network settings and
help increase the speed and accuracy of data transmission
• Medical Used as imaging tools and also as lasers for surgeries
7.
8. Benefits of Optical Fiber
• Fiber Supports Very High Bandwidth Levels
• Provides signal security
• Immunity to crosstalk
• Fiber withstands water and temperature Fluctuations
• Fiber is immune to EMI
• Attenuation in optical fiber is lower than coaxial cable or twisted pair
• Smaller physical size
9. 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.
11. Single Mode Optical Fiber
• Core: 9 µm diameter
• Cladding: 125 µm dia.
• Buffer: 250 µm dia.
• Jacket: 400 µm dia.
• Single Mode fiber optic cable has a
small diametral core that allows only
one mode of light to propagate.
• Used to transmit over long distances
• Higher bandwidth runs by Telcos,
CATV companies, and Colleges and
Universities.
• Low dispersion & attenuation
• Distance up to 40 Km
• Best for WAN & MAN
12. Multi Mode Optical Fiber
• Core: 50 or 62.5 µm dia.
• Cladding: 125 µm dia.
• Coating: 250 µm dia.
• Multimode fiber optic cable has a
large diametral core that allows
multiple modes of light to propagate
• Used to transmit over short distances
• Higher dispersion & attenuation
• 10 Gbit/s up to 550m
• 1 Gbit/s up to 1000 m
• Best for data and audio/video
applications in LANs
13. Optical Fiber
Multimode
OM1 OM2 OM3 OM4
Single Mode
OS1 OS2
Types of MM & SM
Optical Fiber
• Color: Orange
• Core: 62.5 µm
• Range: 33m
• Rates: 10 Gig
• Color: Orange
• Core: 50 µm
• Range: 82m
• Rates: 10 Gig
• Color: Aqua
• Core: 50 µm
• Range: 300
• Rates: 10 Gig
• Range: 100 m
• Rates: 40-100 Gig
• Color: Aqua
• Core: 50 µm
• Range: 550 m
• Rates: 10 Gig
• Range: 150 m
• Rates: 100 Gig
• Indoor
• Tightly buffered
• Tolerant of bending
• Campus & Data Center
• Greater loss 1.0 db/Km
• Outdoor
• Loose tube
• Bend Sensitive
• Street Under ground
• Greater loss 0.4 db/Km
14. Modes of Propagation
• Step-Index: Due to its large core,
some of the light rays that make up
the digital pulse may travel a direct
route, whereas others zigzag as they
bounce off the cladding
• Graded-Index: Due to the graded
index, light in the core curves helically
rather than zigzag off the cladding,
reducing its travel distance
• Single mode – there is only one path
for light to take down the cable
16. Fiber Connectors
• Every connector is
defined by its ferrule
diameter
• Ferrules (made of
ceramic) hold the end
of the fibers and keep
them aligned
• Different connectors for
single mode & multi
mode fibers.
• Most common are
LC: Lucent Connector
SC: Square Connector
ST: Straight Tip
FC: Ferrule connector