In this powerpoint, I explained the overall concept of optical communication.

1. PRESENTED BY :
ANITHA (15JM1A0448)

2.  INTRODUCTION.
 EVOLUTION.
 STRUCTURE OF OPTICAL FIBER.
 WORKING PRINCIPLE.
 CLASSIFICATION.
 BLOCK DAIGRAM.
 ADVANTAGES.
 APPLICATIONS.
 CONCLUSION.

3.  Optical fiber communication is the process of
exchanging information from source to
destination by transmitting light pulses over
an fiber.

4.  Historically, development of optical fiber
communication took place in subsequent
phases with the advent in the enhancement
of technology.
 In 1880 Alexander Graham Bell proposed this
OC.
 In 1960 laser was first used as light source.
 In 1970’s high loss of light discovered.
 In 1980’s OC technology becomes backbone
of long distance telephone networks.

6. Optical fiber works on the principle of Total Internal
Reflection.
When the angle of incidence is greater than critical
angle the light ray travels through it.

8. The refractive index.
Based on number of modes.
Optical fiber classified into two
categories:

9.  On basis of number of modes they are 2
modes:
1) Single mode fiber.
2) Multi mode fiber.
 Single mode: In single mode fiber only one
mode can propagate through the fiber. This
type of fiber has small core diameter (8-
12um)&high cladding diameter (125um).
 The refractive index of core & cladding is
very small.
 The light is passed through a single mode
fiber through laser diode.

10.  Multi mode: It allows large number of modes
for the light ray travelling through it.
 The core diameter is (40um)&cladding is
(70um).
 The refractive index between core &cladding
is large.
 There is signal degradation because of
multimode dispersion.
 These are not applicable for long distance
communication due to large dispersion &
attenuation of the signal.

11.  Based upon refractive index they are 2 types:
1. Step index.
2. Graded index.
 Step index: The refractive index of core is constant.
 The refractive of cladding is also constant.
 The light rays propagate through in the form of
meridiognal rays which cross the fiber axis during
every reflection at the core cladding boundary.

12.  Graded index fiber:
 In graded index fiber the core refractive index is non-
uniform refractive index .
 The cladding refractive index is uniform.
 The light rays propagate through it in the form of
skew rays or helical rays.
 They do not cross the fiber axis at any time.

15.  Optical fibers have huge information-carrying
capability.
 OFC provide high degree of signal security.
 OFC have small size and low weight.
 Optical fibers are less expensive as it has low
manufacturing cost.
 Optical fiber exhibits low transmission loss.
 The life of fiber is longer than copper wire.
 Optical fibers are flexible.

16.  Optical fibers are used in telecommunication.
 These are used for point-to-point communication.
 Control & instrumentation fields.
 Also used in military applications.
 Defense services for data transmitting.
 Cable T.V ,ships, submarine cables.
 Space vehicles.
 Security and alarm systems.

17.  Fiber optics communication is an ever evolving one,
it is the future of data communication.
 This advances a technology have enabled more data
to conveyed through a single optical fiber over
along distance.
• Below are some future trends of OC: Multi-Terabit
optical networks, Intelligent optical transmission,
laser neural network nodes, polymer optic fibers.