All about fibre optics prepares by some university students.It covers all the aspects of optical fibre which includes the working principle, advantages of optics, application and how total internal reflections occurs in a wire.

1. Fiber Optic Cable
Presented By:
• Arsalan Fakhar Siddiqui
• Osama Muhammad
• Muhammad Shehryar
• Muhammad Usman
• Faizan Ahmed

2. Fiber optics (Optical fiber)
• Fiber optics, or optical fiber, refers to the
medium and the technology associated
with the transmission of information as
light pulses along a glass or plastic strand
or fiber. A fiber optic cable can contain a
varying number of these glass fibers --
from a few up to a couple hundred.
Surrounding the glass fiber core is another
glass layer called cladding. A layer known
as a buffer tube protects the cladding, and
a jacket layer acts as the final protective
layer for the individual strand.

5. Working Principle
• A fiber-optic system is similar to the copper
wire system that fiber-optics is replacing. The
difference is that fiber-optics use light pulses
to transmit information down fiber lines
instead of using electronic pulses to transmit
information down copper lines. Looking at the
components in a fiber-optic chain will give a
better understanding of how the system works
in conjunction with wire based systems.
• At one end of the system is a transmitter. This is
the place of origin for information coming on to
fiber-optic lines. The transmitter accepts coded
electronic pulse information coming from copper
wire. It then processes and translates that
information into equivalently coded light pulses. A
light-emitting diode (LED) or an injection-laser
diode (ILD) can be used for generating the light
pulses. Using a lens, the light pulses are funneled
into the fiber-optic medium where they travel
down the cable.

7. • A fundamental optical parameter one
should have an idea about, while studying
fiber optics is Refractive index. By
definition, “The ratio of the speed of light
in a vacuum to that in matter is the index
of refraction n of the material.” It is
represented as −
• n=cvn=cv
• Where,
• c = the speed of light in free space = 3 ×
108 m/s
• v = the speed of light in di-electric or non-
conducting material
• Generally, for a travelling light
ray, reflection takes place when n2 < n1 .

8. Types of optical fibers
Single mode optical fiber
• As the name suggests, this type of optical fiber transmits only
one mode of light. To put it another way, it can carry only one
wavelength of light across its length.
• This wavelength is usually 1310nm or 1550nm.
• You would think that this limits its capabilities of transferring
more data. But single mode type of optical fibers is much better
than multimode optical fibers as they have more bandwidth and
experience fewer losses. So the speed is unmatched.
• Interestingly, single mode fibers came into
existence after multimode fibers. They are more recent than the
multimode cables.
• Only lasers are used as a light source. To point out, the light used
in single mode fibers are not in the visible spectrum.
• Since the light travels in a straight direction, there are fewer
losses, and it can be used in applications requiring longer
distance connections.
• An obvious disadvantage of single mode fiber is that they are
hard to couple.

9. Multimode optical fiber
• As the name implies, these types of optical fibers allow multiple
modes of light to travel along their axis.
• To explain physically, they can do this by having a thicker core
diameter.
• The wavelengths of light waves in multimode fibers are in the
visible spectrum ranging from 850 to 1300 nm.
• The reflection of the waves inside the multimode fiber occurs at
different angles for every mode. Consequently, based on these
angles the number of reflections can vary.
• We can have a mode where the light passes without striking the
core at all.
• We can have a slightly higher mode which will travel with
appropriate internal reflections.
• Since the basis of optical fiber communication is a total internal
reflection, all modes with incident angles that do not cause total
internal reflection get absorbed by the cladding. As a result,
losses are created.
• We can have higher order modes, waves that are highly
transverse to the axis of the waveguide can reflect many times.
In fact, due to increased reflections at unusual angles, higher
order modes can get completely lost inside the cable.
• Lower order modes are moderately transverse or even
completely straight and hence fare better comparatively.
• There are two types of multimode optical fibers: stepped index
and graded index.

10. • Stepped index multimode fiber
• The refractive index of the core of the multimode is uniform throughout the cable.
• Graded-index multimode fiber
• The refractive index of the core changes radially from the center of the core to its
surface.

11. Micro-structured optical fibers
• These are the new types of optical fiber
cables. They have an entirely different
concept of using light for communication. In
the types of optical fibers mentioned above,
light travels due to total internal reflection
and refractive indices of the core and
cladding. In microstructure optical fibers, the
physical structure of the waveguide is used at
a Nano-scale level to manipulate light.
Different types of microstructure optical
fibers are
• Photonic Crystals
• Air-clad or double clad fibers
• Fresnel fibers

12. Advantages
• Functional Advantages
• The functional advantages of optical
fibers are :
• The transmission bandwidth of the
fiber optic cables is higher than the
metal cables.
• The amount of data transmission is
higher in fiber optic cables.
• The power loss is very low and hence
helpful in long-distance transmissions.
• Fiber optic cables provide high security
and cannot be tapped.
• Fiber optic cables are the most secure
way for data transmission.
• Fiber optic cables are immune to
electromagnetic interference.
• These are not affected by electrical
noise.
• Physical Advantages
• The physical advantages of fiber optic cables are −
• The capacity of these cables is much higher than
copper wire cables.
• Though the capacity is higher, the size of the cable
doesn’t increase like it does in copper wire cabling
system.
• The space occupied by these cables is much less.
• The weight of these cables is much lighter.
• Since these cables are di-electric, no spark hazards are
present.
• These cables are more corrosion resistant than copper
cables, as they are bent easily and are flexible.
• The raw material for the manufacture of fiber optic
cables is glass, which is cheaper than copper.
• Fiber optic cables last longer than copper cables.

13. Fiber Is Everywhere!
It’s how we communicate…

14. Applications of Fiber Optics
1. 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, more
flexible, and carry more data.
2. 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.
3. 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.
4. 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.
5. Surgery and Dentistry
• Fiber optic cables are widely used in the fields of medicine and research.
Optical communication is an important part of non-intrusive surgical
methods, popularly known as endoscopy.
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
solution to lighting projects. As a result, they are widely used in lighting
Christmas trees.
7. Mechanical Inspections
• Fiber optic cables are widely used in the inspection of hard-to-reach
places
8. 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.
9. Automotive Industry
• Fiber optic cables play an important role in the lighting and safety
features of present day automobiles. They are widely used in lighting.
Because of its ability to conserve space and provide superior lighting.
Also, fiber optic cables can transmit signals between different parts of
the vehicle at lightning speed

15. Under The Oceans

16. On The Land
©2015, The Fiber Optic Association, Inc.

17. Thank you