This document summarizes optical fiber communication. It discusses how optical fibers transmit information using pulses of light and the advantages of optical fiber such as small size, light weight, large bandwidth and faster speed compared to electrical cables. It also describes the basic structure of optical fibers including the core and cladding. Additional topics covered include light propagation through total internal reflection, acceptance angle, types of optical fibers, sources of loss, variations in attenuation based on wavelength, sources of noise and applications of optical fiber communication.

1. Raj Kumar
6th
Sem ECE
SEMINAR ON OPTICAL FIBERSEMINAR ON OPTICAL FIBER
COMMUNICATIONCOMMUNICATION
KRISHNA ENGINEERING COLLEGEKRISHNA ENGINEERING COLLEGE

2. Introduction
Fiber-optic communication is a method of transmitting
information from one place to another by sending pulses
of light through an optical fiber. The light forms an
electromagnetic carrier wave that is modulated to carry
information. First developed in the 1970s, fiber-optic
communication.

3. Advantage of optical fiber
communication
 Small Size
 Light Weight
 Easy availability
 No electrical
 Large bandwidth
 100 Times Faster

4. DISADVANTAGE OF OPTICAL FIBER
COMMUNICATION SYSTEM
 Price
Joining difficult
 Affected by chemical
 Fragility

5. Construction of Optical Fiber
Basic Structure of fiber optic cable
 Core
 Cladding
 Buffer
 Jacket

6. Light propagation in a fiber
The light in a fiber-optic travels through the
core by constantly bouncing from the cladding,
a principle called total internal reflection.
Because the cladding does not absorb any
light from the core, the light wave can travel
great distances

7. Acceptance angle
• The maximum angle of incidence that a
ray can make that will result in total
internal reflection is called acceptance
angle

8. Type of optical fiber
Single Mode Fibers
These are called as single mode fibers
because they support on one mode of
propagation.
Multimode fibers
These are called as multimode fibers because
they support simultaneous propagation of
many modes

9. Loss In optical fibers
Attenuation
Absorption
Scattering Losses
Bending Losses
Dispersion

10. ATTENUATION
• Attenuation in an optic fibre is caused by
the impurities of the glass core. The
amount of attenuation depends on the
wavelength of the light being transmitted.
• Power loss in decibels is defined as
• Power loss = 10log (Pfinal / Pinitial) in dB
• Thus a power loss of 16 decibels means
that the initial power of, say,8.0mW has
been reduced to 0.2mW

11. VARIATION OF SPECIFIC
ATTENUATION WITH
WAVELENGTH

12. Attenuation & Wavelength
• The specific attenuation ( power loss in dB
per unit length ) actually depends on the
wavelength of the radiation travelling
along the optic fibre
• The graph shows minima at 1310nm and
1550nm, which implies that these are
desirable wavelengths for optimal
transmission
• These are infra red wavelengths

13. NOISE
• Source of noise in a cable:
• Random motion of electrons which
creates additional electric fields
contaminating the signal. This increases
with temperature.
• Lightning
• Charged particles emitted by the sun
during intense solar activity

14. Working of optical communication

15. Working of optical communication
In the Working of optical communication system
information signal give to the amplifier for amplify the
signal and give to the light source it convert information
signal in to light and give to the transmitter for transmitter
signal and signal pass through the fiber with line coupler
and signal travel long distance through fiber on the
receiver section signal receive and give to photo detector
convert the light energy to electrical energy and signal are
amplify on output .

16. Use device in fiber communication
system
Optical Source
Transmitter
Line coupler
Optical Fiber
Receiver
Optical Detector

17. Application of optical fiber
communication
Biomedical Industries
Broadcast Television
Computer Networks
o LAN
o MAN
o WAN
 Telephone Exchange

18. THE END