This presentation provides an overview of optical fibers, including their structure, working principle, classification, communication systems, advantages and applications. Optical fibers are thin strands of glass that carry light signals for transmission. They have a core that carries the light surrounded by cladding with a lower refractive index to keep light within the core via total internal reflection. Fibers are classified by number of transmission modes as single-mode or multi-mode, and by refractive index profile as step index or graded index. Optical fiber communication systems allow transmission over long distances with low loss. Key advantages are high bandwidth, electrical isolation, low power consumption and high security. Applications include data transmission, telecom, broadband, medical and more.

1. Presented by
Group-2B
ANAL MANDAL
ANIRBAN NATH
ANAMIKA ANAND
PRESENTATION
on
OPTICAL FIBRE
ECE Dept. - Techno Engineering College Banipur

2. BRIEF OVERVIEW
1
Cover & Contents Page 0-1
What is Optical Fiber Page 02
Structure of optical fiber Page 3-4
Working principle of optical fiber Page 05
Classification Page 06-10
Communication system & Attenuation Page 11-12
Advantage/Disadvantage of opticalfiber Page 13-14
Applications Page 15
Conclusion Page 16
Reference Page 17

3. WHAT IS OPTICAL FIBER
2
 An optical fiber is a hair thin
cylindrical fiber of glass or plastic
 The fiber which are used for
optical communication are wave
guides made of glass/plastic
 Its function is to guide visible and
infrared light over longdistance

4. STRUCTURE OF OPTICAL
FIBER
3

5. 4
Core- Central tube - Very thin size - Diameter 5 μm
to 100 μm - Carries the light form transmitter to
receiver
Cladding- Outer optical material of core - Refractive
index lower than core – Keeps light within the core
Buffer Coating- Plastic/Rubber coating - Protects the
fiber - Diameter of fiber after coating is 250-300 μm
CONTINUE…

6. WORKING
PRINCIPLE
5
Total Internal Reflection(TIR)
When an ray of light travels from a denser to a rarer medium such that
the angle of incidence is greater than the critical angle, the ray reflects
back into thesame medium, this phenomena is called TIR
In the optical fiber the rays undergo repeated total number of
reflections until it emerges out of the other end of the fiber, even if
fiber is bend

7. CLASSIFICATION OF
OPTICAL FIBER
6
Optical fiber is classified into twocategories based on:-
1) The number of modes-
 Single-Mode Fiber (SMF)
 Multi-Mode Fiber (MMF)
2) The reflectiveindex-
 Step Index Optical Fiber
 Graded Index Optical Fiber

8. ON BASIS OF
NUMBER OF MODES
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 In single mode fiberonlyone modecan propagate through the
fiber
 It has small core diameter (5 μm) and high cladding diameter
(70 μm)
 Difference between the refractive indexof coreand cladding is
very small
 There is neither dispersion nor degradation therefore it is suitable
for long distancecommunication.
Single
Mode
Fiber

9. MULTI- MODE FIBER
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It allows a large number of modes for
light ray travelling throughit
The core diameter is 40 μm and that
of cladding is 70 μm
The relative refractive index
difference is also large than single
mode fiber
There is signal degradation due to
multimodedispersion
It is not suitable for long distance
communication due to large
dispersion and attenuation of signal

10. ON THE BASIS OF REFRACTIVE INDEX
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There are two type of opticalfiber:-
1) Step Index Optical Fiber
2) Graded Index Optical Fiber
Source:
www.ee.ryerson.ca

11. STEP INDEX FIBER
10
The refractive index of core and cladding areconstant
The light ray propagate through it in the form of zig-zag
rays which cross the fiber axis during every reflection at
the core claddingboundary
Core has a non uniform refractive index that gradually
decrease from the center towards the core - cladding
interface
Thecladding has a uniform refractive index
The light rays propagate through it in the form of
parabolic rays & nevercross the fiberaxis
GRADED INDEX FIBER

12. OPTICAL FIBER COMMUNICATION SYSTEM
11

13. ATTENUATION
12
Attenuation is the loss of the opticalpower
Attenuation in optical fiber take place due to elements
like coupler, splices, connector and fiber itself

14. ADVANTAGE OF OPTICAL FIBER
13
 Immense bandwidth toutilize
 Total electrical isolation in the transmission
medium
 Very low transmission loss
 Small size and lightweight
 High signal security
 Very low power consumption and wide scope
of system expansion

15. 14
1) System installation is very costly
2) Only point-to-point communication is possible
3) Costly instruments would be required
4) Splicing is timeconsuming
5) Itaccept only unipolarcodes
DISADVANTAGES OF OPTICAL FIBER

16. APPLICATIONS
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 Data Transmission
 In telecommunication field
In militaryapplications
Broadband applications
Broadcasting / TV
Medical applications etc

17. CONCLUSION
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At the last, there are some negative points of
using optical fiber communication system in terms
of splicing, coupling, set up expenses etc. But it is
an unavoidable fact that optical fiber has
revolutionized the field of communication. As soon
as computers will be capable of processing optical
signals, the total arena of communication will be
opticalizedimmediately.

18. REFERENCE:-
1. https://nptel.ac.in/courses/117101002/downloads/Lec03.pdf
2. https://www.svce.ac.in/departments/physics/ph16151/Unit%205%
20Optical%20fibres.pdf
3. http://www.physics.usyd.edu.au/~jbh/share/PHYS1901/chapter8-
Fibre-Optics.pdf
4. https://www.youtube.com/watch?v=jZOg39v73c4
5. https://www.youtube.com/watch?v=GTG5rPgvYm0
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Websites:-
Books:-
1. Optical Fiber communication by Gerd Keiser
2. Optical Fiber communication by M. Senior

19. THANK YOU…..
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