This powerpoint Deals with basic Concepts of optical Fibers.It was prepared to assist students to get knowledge about Optical fibers and their working principle as well. Read it ,, share it ,, Cheers...(C) Regmi Milan

1. By; Milan Regmi

2.  An optical fiber is a thin, flexible, transparent fiber
that acts as a "light pipe", to transmit light between the
two ends of the fiber which are made up of glass or
plastic.
 Fibers are used instead of metal wires because signal
travels along them with less loss of intensity and are
also immune to electromagnetic interference.
 Specially designed fibers are used for a variety of other
applications, including sensors and fiber lasers.
 Application of optical fibers is known as fiber optics.
 Optical fibers are widely used in fiber-optic
communications, which permits transmission over
longer distances and at higher bandwidths.

3. Pic1-A bundle of optical fiber Pic2-An optical fiber cable
Pic3-A single mode fiber

4.  Optical fibers are designed to work under the principal
of “Total internal Reflection”.
 Optical fiber typically consists of a transparent core
surrounded by a transparent cladding material with a
lower index of refraction.
 Light is kept in the core by the phenomenon known as
“Total internal reflection”.
 Joininglengths of optical fiber is more complex
than joining electrical wire or cable.
 in order to join the ends of the fibers they must be
carefully spliced together by fusing them together
with heat.
 Special optical fiber connectors are used to make
removable connections.

5.  Fiber optics, though used extensively in the modern
world, is a fairly simple and old technology.
 This technology was first of all demonstrated by
Daniel Colladon and Jacques Babinet in Paris in the
early 1840s introducing the total internal reflection
phenomenon for the first time.
 Many scientists worked on it and they correctly and
systematically theorized the light-loss properties for
optical fiber, and pointed out the right material to
manufacture such fibers -silica glass with high purity
 This discovery led to Charles k. Kao being awarded
with the Nobel Prize in Physics in 2009.

6.  Optical fiber communication:-
 Optical fiber can be used as a medium for telecommunication
and networking because it is flexible and can be bundled as
cables.
 It is especially advantageous for long-distance communications,
because light propagates through the fiber with low loss of
intensity compared to electrical cables.
 This allows long distances to be spanned with few repeaters.
 Channel light signals propagating in the fiber have been
modulated at rates as high as 111 gigabits per second by,
although 10 or 40 Gbit/s is typical in deployed systems.
 Each fiber can carry many independent channels, each using a
different wavelength of light.
 For short distance applications, such as creating a network
within an office building, fiber-optic cabling can be used to save
space in cable ducts. This is because a single fiber can often
carry much more data than many electrical cables.

7.  Optical fibers can be used as sensors to measure strain
temperature ,pressure and other quantities by modifying a fiber so
that the quantity to be measured modulates the intensity, phase, or
transit time of light in the fiber.
 Fibers are widely used in illumination applications. They are used
as light guides in medical and other applications where bright light
needs to be shone on a target without a clear line-of-sight path.
 Finally,we can conclude that optical fibers have been boon for the
IT prosperity of any nation.

8.  When light traveling in a denser medium hits a
boundary at a steep angle (larger than the "critical
angle" for the boundary), the light will be
completely reflected.
 The phenomenon of reflection of light from
denser/rarer medium to the same medium itself is
called Total internal reflection.
 And this happens only when angle of incidence is
greater or equals to angle of refraction.