Fiber optics use thin strands of glass called optical fibers to transmit light signals over long distances. There are two main types of optical fibers: single-mode fibers used for long distances and multi-mode fibers used for short distances. Optical fibers consist of a core where light travels, a cladding that reflects light back into the core, and a protective buffer coating. Light pulses through the fiber and reflects off the cladding to travel long distances without needing repeaters. Fiber optics have advantages over copper wiring like higher bandwidth, lower signal loss over long distances, lower material costs, and greater security since light cannot be tapped. Fiber optics are widely used for internet connectivity, cable TV, telephone networks, and computer networking.

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1.1. IntroductiontoFiber Optics
During our current age, the increasing ability to transmit more information over longer
distances more quickly has expanded the boundaries of our technological development in many
areas such as data networks, wireless and satellite communications, cable operators, and
broadcasters. All of this has become possible by the use of fiber optics. [1]
1.2. What is Fiber Optics?
Fiber Optics, also called optical fibers, is microscopic strands of very pure glass with about the
same diameter of a human hair. Thousands of these optical fibers are arranged in bundles in
optical cables and are used to transmit light signals over long distances. The bundles are
protected by a jacket, which is the cable's outer covering. [2]
Fig 1.1: - Fiber Optics Fig 1.2: - Fiber Optics
1.3. Type of optical fiber
Single-mode and multi-mode are the two types of optical fibers.
i) Single-mode Optical Fiber
The single-mode, used for long distances, has small cores and transmits infrared laser light.
ii) Multi-mode Optical Fiber
The multi-mode, normally used for short distances, has large cores and transmits infrared light.
[3]
1.4. Constructionof Optical Fiber
There are three part of optics fiber :-
1) Core:- Thin glass centre of optics fiber where Light travels.

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2) Cladding:- outer optical material surrounding the core and it reflect the light back into it is
the cladding.
3) Buffer coating:- Plastic coating that protects the fiber from moisture and damage. [4]
Fig 1.3: - Fiber Optics
1.5. How Optics Fiber works:
A glass tunnel through which the light travels is created. When the light hits the cladding, it
interacts with and reflects back into the core. Because of this design, the light can “bend”
around curves in the fiber and makes it possible to travel further distances without having to be
repeated. The light that travels along the fiber is made up of a binary code that pulses “on” and
“off” and determines what information a given signal contains. [5]
Fig .1.4:- Simple representation of optical fiber transmission
1.6. Advantages over copper wiring
The advantages of optical fiber communication with respect to copper wire systems are:
1) Broadbandwidth: - A single optical fiber can carry over 3,000,000 full-duplex voice calls
or 90,000 TV channels.

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2) Low reduction loss over long distances:- Reduction loss can be as low as 0.2 dB/km
in optical fiber cables, allowing transmission over long distances without the need
for repeaters.
3) Material cost and theft prevention: - Conventional cable systems use large amounts
of copper. Global copper prices experienced a boom in the 2000s, and copper has been a target
of metal theft.
4) Security information passed down the cable:- Copper can be tapped with very little
chance of detection. [6]
5) Speed: - Fiber optic networks operate at speeds up to 10 gigabits per second or higher, as
opposed to 1.54 megabits per second for copper. Fiber can carry information so fast that you
could transmit three television episodes in one second.
6) Bandwidth: - Taken in bulk, it would take 33 tons of copper to transmit the same amount
of information handled by 1/4 pound of optical fiber. [7]
1.7. Uses of Fiber Optic Cables
It is widely used in:-
1) 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.
2) Internet: - Fiber optic cables transmit large amounts of data at very high speeds. This
technology is therefore widely used in internet cables. As compared to traditional copper wires,
fiber optic cables are less bulky, lighter, and more flexible and carry more data.
3) Cable Television: - The use of fiber optic cables in the transmission of cable signals has
grown explosively over the years. These cables are ideal for transmitting signals for high
definition televisions, because they have greater bandwidth and speed. Also, fiber optic cables
are cheaper as compared to the same quantity of copper wire.
4) Telephone: - Calling telephones within or outside the country has never been so easy.
With the use of fiber optic communication, you can connect faster and have clear conversations
without any lag on either side.
5) Computer Networking: - Networking between computers in a single building or across
nearby structures is made easier and faster with the use of fiber optic cables. Users can see a
marked decrease in the time it takes to transfer files and information across networks.
6) Lighting and Decorations: - The use of fiber optics in the area of decorative illumination
has also grown over the years. Fiber optic cables provide an easy, economical and attractive
solution to lighting projects. As a result, they are widely used in lighting decorations and
illuminating Christmas trees. [8]

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Reference
[1]:- http://www.cableorganizer.com/articles/fiber-optics-tutorial/history-production-fiber-
optic.html
[2]:- http://www.cableorganizer.com/articles/fiber-optics-tutorial/history-production-fiber-
optic.html
[3]:- http://www.cableorganizer.com/articles/fiber-optics-tutorial/history-production-fiber-
optic.html
[4]:- http://www.slideshare.net/kingwardakk/presentation-about-fiber-optics
[5]:- http://www.jmfiberoptics.com/Links/FOInfo/intro.htm
[6]:- https://en.wikipedia.org/wiki/Optical_fiber
[7]:- http://www.jmfiberoptics.com/Links/FOInfo/intro.htm
[8]:- http://www.doityourself.com/stry/9-uses-of-fiber-optic-cables
[9]:https://www.google.com.pk/search?q=fiber+optics&biw=1366&bih=662&source=lnms&tb
m=isch&sa=X&ved=0ahUKEwib7_2Zu9XRAhWkKMAKHZdKB70Q_AUIBigB&dpr=1#tbm=isch&q=
how+fiber+optics+work&imgdii=8fFfDm50a3eq_M%3A%3B8fFfDm50a3eq_M%3A%3BNkxChcQ
RPUGMmM%3A&imgrc=8fFfDm50a3eq_M%3A
Note: - Website no.9 is website from where I have taken my assignment picture