Optical fibers transmit light between two ends and are used widely in fiber-optic communications. They consist of a core and cladding, with the core having a higher refractive index to keep light within the core through total internal reflection. Optical fibers have advantages over metal wires like lower signal loss, higher bandwidth, and immunity to electromagnetic interference. They are used for long-distance, high-bandwidth data transmission and for applications like imaging in confined spaces.

1. OPTICAL FIBRE
DEPT. OF ELECTRONICS AND
COMMUNICATION
By: Saumya Ranjan Behura
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2. CONTENT
Introduction
Construction
Types of optical fiber
Working
Charactertics
Uses
Advantages & Disadvantages
FutureScope
Conclusion
Reference

3. INTRODUCTION:
An optical fibre is a thin, flexible, transparent fiber that
acts as a waveguide, or "light pipe“, to transmit light
between the two ends of the fiber.
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 loss less and are also immune to
electromagnetic interference.
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4. Fibers are also used for illumination and are wrapped in bundles so
that they may be used to carry images, thus allowing viewing in
confined spaces, as in the caseof afiberscope.
Optical fiber typically include a core
surrounded by a transparent cladding
material with a lower index of
refraction.
Light is kept in the core of phenomenon
of total internal reflection which causes
the fiber to act asa waveguide.

5. TOTAL INTERNAL REFLECTION:
 When a ray of light travels from a denser to a rarer medium such that the
angle of incidence is greater than thecritical angle, the ray reflects back into
same medium, this phenomenon is called asTIR.
 In optical fiber the rays undergo repeated total number of reflections until
it emergesout of the other endof the fiber , evenif it is bent.

6. CONSTRUCTION:
Fiber optic cable consists of acore, cladding, coating,
buffer strengthening fibers and cable jacket.
CORE : It is the physical medium that transports optical
datasignals from anattached light source to areceiving
device.
CLADDING: It is athin layer that surrounds the fiber core
and serves asaboundary that contains the light waves &
causes the refraction.
COATING: It isa layer of plastic that surrounds the core
& cladding to reinforce the fiber core.

7. STRENGTHENING FIBERS: It helps to protect the core
against crushing forces and excessivetensionduring
installation.
CABLE JACKET: It is theouter layer of any cable.Various
colors can be used to designate different application
withina network.

8. TYPES OF OPTICAL FIBER:
MULTIMODE:
Multimodecable has a large diameter core and
multipaths of light.
It is commonly available in two core sizes :
50 micron and 62.5 micron.
It can be used for most general data and voice fiber
application.
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9. SINGLE-MODE :
Single modecablehas smallglass core andonly
one pathwayoflight.
It provides 50 timesmore distancethanmulti-
modecables.
It isused in highbandwidthapplicationand in
long-haulnetworkconnectionspread out over
extendedareasincluding televisions.

10. BLOCK DIAGRAMOFOPTICAL FIBERCOMMUNICATION:

11. OPTICALFIBERCOMMUNICATIONCONSISTS OF
THREE MAIN ELEMENTS:
1. TRANSMITTER
Drivecircuitdrivesthelightsource.
Lightsourceconvertselectricalsignaltooptical.
Fiberflyleadisusedtoconnectopticalsignaltoopticalfiber.
2.TRANSMISSION CHANNEL:
Optical connector is for temporary non- fixed joints between two optical
fiber.
Opticalspliceisusedtopermanentlyjointwoopticalfiber.

12. 3. RECEIVER:
Opticalsignalis applied to the optical receiver.
Photo detector converts the optical signalto electrical signal.
Signal restorers and amplifiers are used to improve signal to
noise ratioof the signal.

13. WORKING:
Theopticalfiberworks on theprincipleoftotalreflection.
Light rays can be used to transmit huge amount of data and
travelsinstraightline.
The optical cables are designed such that they bend all the light
rays inwards.
Light rays travel continuously bouncing off the optical fiber
wallsand transmittingend toend data.

14. CHARACTERISTICS:
WIDER BANDWIDTH: The optical carrier frequency is in the range
10^13 Hz to 10^15Hz.
LOW TRANSMISSION LOSS: The fibers having a transmission loss of
0.002dB/km.
DIELECTRIC WAVEGUIDE: Optical fibers are made from silicawhich is
an electrical insulator.
SIGNAL SECURITY: The transmitted signalthrough the fibers does not
radiate.
SMALL SIZE AND WEIGHT :Fiber optic cables are developed with
small radii, and they are flexible, compact and lightweight.

15. USES:
 Fibersare widelyused inillumination
application
 They are used aslightguidesinmedicaland
other applicationinsome building
 Opticalfiberare used to routesunlightfrom
the roofto other partsof thebuilding

16. ADVANTAGES:
 Wavelength
 Frequency
 Windows
 Attenuation
 Dispersion

17. DISADVANTAGES :
 Highinvestment cost
 Need for more expensive optical
transmitters andreceivers
 More difficultand expensiveto splice
than wires
 Fragility
 Affected by chemicals
 Requires specialskills

18. COMPARISONBETWEEN OPTICAL FIBER,CO-AXIALCABLE
& TWISTED PAIRCABLE:
OPTICAL FIBER CO-AXIAL CABLE TWISTEDPAIRCABLE
•Transmission of signal
overa glass fiber.
•Transmission of signal
over inner conductor
cable.
•Transmission of signal
overconducting wires.
•Expensive •Moderate expensive •Cheapest medium
•Veryhigh bandwidth •Moderate high band-
width.
•Low bandwidth
•Attenuation is verylow. •Attenuation is low. •Attenuation is veryhigh.
•Installation is difficult. •Installation is fairly easy. •Installation is easy.

19. FUTURE SCOPE:
 Alloptical communicationnetworks
 Multi-Terabitoptical network
 Intelligentoptical transmission network
 Polymer optic fibers
 Improvement in optical amplification
 Improvements in glass fiber design and component
 High-Altitude platform

20. CONCLUSION:
 Fiber optics, a branch of optics dealing with the
transmission of light through hair-thin, transparent
fibers.
 A principle called total internal reflection allows
optical fibers to retain the light they carry.
 The development of new optical technique will
expand the capabilityof fiber optic system.

21. REFERENCE:
Wikipedia
N.S. Kapany, Fiber Optics: Principles and application
J.Gower, Opticalcommunicationsystem, 2nd ed., PrenticeHall
https://www.slideshare.net/mobile/manoj_2586/wireless-
charging-ppt-45698396

22. THANK YOU !!