2. TOPICS COVERED
FIBER OPTICS-AN INTRO
HISTORY OF OPTICAL FIBER
STRUCTURE OF AN OPTICAL FIBER
WORKING PRINCIPLE
TYPES OF OPTICAL FIBER
SINGLE MODE
PROCESS INVOLVED
PRO’S AND CON’S
CONCLUSION
3. FIBER OPTICS-AN INTRO:
The technology that transmits information as light pulses along a glass or
plastic fiber is called fiber optics.
OPTICAL FIBER:
An optical fiber is a flexible transparent fibre mainly used as a means of
transmitting light between two ends of the fiber.it is usually made up of silica
or glass and its diameter is slightly thicker than that of human hair. they permit
transmission of data at higher bandwidths than electrical cables,the signals
travel through fiber with less loss and fiber cables are immune to
electromagnetic interference
4. HISTORY OF OPTICAL FIBER:
1840’S: Physicists Jacques Babinet and Jean Daniel Colladon
demonstrated the ability to direct Light along curved water ,for use in
water fountain displays.
1880’s: Engineer William wheeler experimented further with this idea,
creating a system of “light pipes” to direct light from a single Electric lap
to others.
1966: Scientist Charles Kao discovered quartz glass and invented fiber
optics
1988: First transatlantic fiber line becomes operational –Penmarch, France
to Widemourth Bay, England to Tuckerton, New Jersey
5. STRUCTURE OF AN OPTICAL FIBER
Optical fiber is composed of three elements:
The core : The core is at the center of the optical fiber and provides a
pathway for the light to travel.
The cladding : Next is the cladding .it holds the light inside the core and
controls the direction in which light is spread through fiber.
The coating : Lastly we have the coating which acts as a buffer. It
cushions and protects the fibers from humidity and hostile environments.
Two layers of urethane Acrylate (plastic) make up the coating, also known
as the “soft” and “hard” layers. The soft layer cushions the fiber and the
hard layer provides abrasion resistance.
6. WORKING PRINCIPLE
When a 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 the same medium this phenomena is called total internal reflection.
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 the fiber is bent.
7. TYPES OF OPTICAL FIBER
There are mainly two types of Optical Fiber:
(a) Multimode
(b) Single Mode
Multimode
Larger core than single mode cable.
Allows greater dispersion and therefore, loss of signal.
Used for shorter distance application, but shorter than singlemode (up to
2Km)
8. SINGLE MODE
Small core.
Less dispersion.
Carries a single ray of light, usually generated from a laser.
Employed for long distance applications (100Km).
Uses as Backbone and distances of several thousands meters.
9. PROCESS INVOLVED
Encoding: The data to be transmitted is encoded into an electrical signal
by a transmitter. This electrical signal is then sent to a laser or LED, which
converts the electrical signal into a series of light pulses.
Transmission: The light pulses are sent through the core of the fiber optic
cable, which is made of glass or plastic. The core is surrounded by a
cladding layer, which is also made of glass or plastic and helps to reflect
the light back into the core, preventing it from leaking out of the cable.
Reception: At the other end of the fiber optic cable, the light pulses are
detected by a photodetector. The photodetector converts the light
pulses back into an electrical signal, which is then decoded by a receiver
to recover the original data.
10. ADVANTAGES
Bandwidth: Optic-Fiber cables have a much greater bandwidth than metal
cables. The amount of information that can be transmitted per unit time of
fiber over other transmission media is its most significant advantage.
Low Power Loss: This allows for longer transmission distances. In comparison to
copper; in a network, the longest recommended copper distance is 100m
while with fiber, it is2000m.
Interference: Fiber optic cables are immune to electromagnetic interference.
It can also be run in electrically noisy environments without concern as
electrical noise will not affect fiber.
Weight: Fiber optic cables are much thinner and lighter than metal wires.
Lighter weight makes fiber easier to install. Safety: Since the fiber is a dielectric,
it does not present a spark hazard
11. DISADVANTAGES
Cost: Cables are expensive to install but last longer than copper cables.
Transmission: transmission on optical fiber requires repeating at distance
intervals.
Fragile: Fibers can be broken or have transmission loses when wrapped
around curves of only a few centimeters radius.
Protection: Optical fibers require more protection around the cable
compared to copper.
12. CONCLUSION
Overall, optical fiber, which is nowadays used worldwide, brought several
important improvements to data transmission.however, its high cost seems to
be the only brake to its deployment. moreover, optical fiber is still in its
beginning, many improvements are made in R&D (research and
development).Our data will be faster than ever.