Download Optial fiber - BSNL Durg SSA(Connecting India)

Submitted to:Smt A.Dhanak
Presented by:Namrata pandey
Nikita karangle
Yasmeen shah
4th semester(cse)
CCET,Bhilai(C.G)
SESSION(2014)
oIntroduction
oHistory
oConstruction of optical fiber
oPrinciple of optical fiber
oTypes of optical fiber
oLocalization of optical fiber fault
oOptical fiber faults
oReasons of fault
oRectification of optical Instrument used
oScope for future
An optical fiber is a flexible, transparent
fiber made of very pure glass {silica}.
It acts as a waveguide, or "light pipe", to
transmit light between the two ends of the
fiber.
Optical fibers are widely used in fiberoptics communications, which permits
transmission over longer distances and at
higher bandwidths(data rates) than other
forms of communication.
Daniel Colladon first described this “light fountain” or “light
pipe” in an 1842 article titled On the reflections of a ray of light
inside a parabolic liquid stream. This particular illustration
comes from a later article by Colladon, in 1884.
Guiding of light by refraction, the principle that makes fiber
optics possible, was first demonstrated by Daniel Colladon
and Jackquse Babinet in Paris in the early 1840s.
Daniel colladon working with his collegue
CORE:The fiber core is made of silica glass and is
the central part of the fiber optic cable
that carries the light signal. They are hairthin in size and the diameter of the fiber
core is typically 8 μm for single mode
fiber, and 50m or 62.5 m for multi mode
fiber core.
CLADDING:The cladding is also made of glass, and is the layer that
surrounds the fiber core. Together, they form a single solid
fiber of glass that is used for the light transmission. The
diameter of the cladding is typically 125 μm.
BUFFER:The buffer is third layer, buffer coatings are UV-cured urethane
acrylate composite materials applied to the outside of the fiber
during the drawing process. The coatings protect the very
delicate strands of glass fiber
JACKET:The last layer is the cable jacket which are comprised of different
materials depending on the choice of the end user and its
application. They serve only for mechanical protection to the
mechanical core and cladding inside
Figure showing parts of optical fiber
An optical fiber is a cylindrical
dielectric waveguide (nonconducting waveguide) that
transmits light along its axis, by the
process of total internal reflection.
The fiber consists of a core
surrounded by a cladding layer, both
of which are made of dielectric
materials. To confine the optical
signal in the core, the refractive
index of the core must be greater
than that of the cladding.
Internal reflection
• Single Mode:-
In fiber optic communication , a single mode optical fiber also
known as mono-mode optical fiber is that fiber which is designed
to carry only a single ray of light. Single-mode fibers can have a
higher bandwidth than multi-mode fibers but the equipment of
single-mode fiber is costlier than multi-mode. Although singlemode fiber are cheaper in bulk.
• Multi-mode:-
Multi-mode optical fiber(MM fiber) is a type of optical fiber
mostly used for communication over short distances, such as
within a building or on a campus. Typical multimode links have
data rates of 10 Mbit/s to 10 Gbit/s over link lengths of up to 600
meters—more than sufficient for the majority of premises
applications. The equipment used for communications over
multi-mode optical fiber is much less expensive than that for
single-mode optical fiber.
Figure showing mode…..
For the effective use of Optical Fiber, it would be
necessary to detect and localize the fiber failures
without delay, and the technique used to detect and
localize the fiber failures is known as Localization.
In general, an optical time-domain reflectometer
(OTDR) has been used to localize fiber failures.
Fault Localization can be demonstrated by using
instruments .Such as optical and metallic time domain
reflectometers (OTDR & MTDR).
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The physical cable or connector damage(Mainly for
the connector and disconnect the connection
cable).
The cable physical damage.
Partial failure of the connector(improper
construction of connectors and cable breakage)
Line graph error(twisted pair cable).
The local cable damage.(mostly due to poor design
or construction technology).
Mostly due to improper construction methods or
accidental damage to network cables and other
causes. Mainly for the connector and disconnect the
connection cable.
2. Mainly due to the tight binding between the short
circuit caused the cable, because cable nails
embedded in gold scrap, stripping header damaged
insulation and cable multi-conductor lead wire
insulation faults exposed.
3. Mainly as a result of the cable twisted, bending
radius is too small to drag force exceeds the
mechanical strength of the cable caused by cable
damage , and many more appear in the new wiring
project.
1.
As mention above, Optical Fiber has different types of
fault, and techniques which are used for recovering
the damages of Optical Fiber are known as
Rectification 0f Optical Fiber.
Some specific instruments are used for Rectification
of Optical Fiber Fault are as follows: Optical time-domain reflectometer (OTDR).
 Optical power meter (OPM) .
 Fusion splicing.
 Pen-type Visual Fault Locator.
An optical time-domain
reflectometer (OTDR) is an
optoelectronic instrument used to
characterize an optical fiber.
An OTDR is the optical equivalent of an
electronic time domain reflectometer.
It injects a series of optical pulses into
the fiber under test.
It also extracts, from the same end of
the fiber, light that is scattered
(Rayleigh backscatter) or reflected
back from points along the fiber.
(This is equivalent to the way that an
electronic time-domain reflectometer
measures reflections caused by
changes in the impedance of the cable
under test.)
The strength of the return pulses is
measured and integrated as a function
of time, and plotted as a function of
fiber length.
An optical power meter(OPM) is a
device used to measure the power in
an optical signal. The term usually
refers to a device for testing average
power in fiber optic systems . A
typical optical power meter consists
of a calibrated sensor, measuring
amplifier and display. The sensor
primarily consists of a photodiode
selected for the appropriate range of
wavelengths and power levels.
Fusion splicing is the act of joining two
optical fibers end-to-end using heat .The
goal is to fuse the two fibers together in
such a way that light Passing through
the fibers is not scattered or reflected
back by the splice . The process of fusion
splicing involves using localized heat to
melt or fuse the ends of two optical
fibers together , the fibers are placed
into the apparatus , aligned, and they
fused together.
Pen type Visual Fault Locator FLP-8312
is simple, easy to use instruments with
stable output designed to locate faults
on fiber optic cables. When a break or
sharp bend exists in a fiber, the red
light from the visible fault locator will
indicate the trouble spot. Used with
either multimode or single mode fiber,
the Visual Fault Locator have many
useful applications such as locating
troubles in splice trays, patch panels,
cable splice points, and tracing fiber
runs.
1. A University on (Mar. 2, 2011) has developed the very
first optical fiber made with a core of zinc selenide --a
light-yellow compound that can be used as a
semiconductor.
The new class of optical fiber, which allows for a more
effective and liberal manipulation of light, promises to
open the door to more versatile laser-radar technology.
Such technology could be applied to the development of
improved surgical and medical lasers.
.
2.Better countermeasure lasers used by the
military.
3.Superior environment-sensing lasers are used
to measure pollutants and to detect the
dissemination of bioterrorist chemical agents.
4.It is found that the new class of fiber
provided more versatility not just in the visible
spectrum, but also in the infrared -electromagnetic radiation with wavelengths
longer than those of visible light.