The document discusses the applications and principles of lasers and optical fibers in communication. It explains how lasers function in various fields, including defense and medicine, and details the advantages and disadvantages of laser communication and optical fiber systems. Key points include the operation of semiconductor lasers and the benefits of optical fibers over traditional copper cables for high-speed, long-distance communication.

1. LASERS AND OPTICAL
FIBRE IN
COMMUNICATIONS
Presented by
P .RAMESH SHASHANK
16691A0376
MECHANICAL ENGINEERING

2. • What is a Laser?
• What is laser communication?
• Laser in many fields
• Laser in communication
• Semiconductor laser
• Disadvantages of laser
communication
• What is OFC?
• Introduction
• OPTICAL FIBRE in
COMMUNICATIONS

3. WHAT IS A LASER?
Light
Amplification by
Stimulated
Emission of
Radiation

4. LASER IN MANY FIELDS :
• From the year Laser has invented i.e. is 1960 it is serving people in many fields
such as
• In Defence it is used in many weapons for the perfect shooting of enemies.
• In Medical it is the major part in many treatments which are mostly by cinema
stars.
• Lasers are used in Mechanical purpose like drilling, welding, cutting, hardening .
• They are also used in Civil purpose like surveying the lands.

5. WHAT IS LASER
COMMUNICATON?
• Laser communications
are wireless which
happens this through
atmosphere. They work
similarly to fibre optics
links, but the other thing
is that communication is
transferred with the help
of laser beams through
free space

6. LASERS IN
COMMUNICATIONS:
• Through laser many uses are there one
of them are communications.
• The information is passed through the
laser beam in atmosphere
• The laser can be created in a range of
wavelengths i.e. ultraviolet region to
infrared region.
• The infrared region is mostly preferred
by the Army as it is more difficult to
detect the signal to enemies.
• To use lasers in communication normal
lasers cannot be used.
• The advent of SEMICONDUCTOR LASERS
has made possible to use the lasers for
signal transmission

7. SEMICONDUCTOR LASERS:
PRINCIPLE:
• In a semiconductor laser there are n–type and p-type semiconductor
lasers
• When the electrons and holes combine in junction region there will
be a release of energy in the form of photons
• The heavily doped semiconductor GalliumArsenide (GaAs) is used in
semiconductor lasers.
• Normal semiconductors Silicon and Germanium cannot be used
because they will release energy in the form of heat when they
combine.
PRINCIPLE:
In a semiconductor laser there are n–type and p-type semiconductor
lasers
When the electrons and holes combine in junction region there will be
a release of energy in the form of photons

8. WORKING:
• The emitted photon during recombination in the junction diode will
trigger laser action near the junction diode.
• The photons emitted have a wavelength from 8200 𝐴0
to 9000 𝐴0
in
the IR region.
Circuit
diagram of
semiconduct
or laser

9. Advantages:
• It is a high speed carrier
• It is having high bandwidth
• Generation of narrow pulses for high bit-rates
• Increased security when working with narrow beams
Disadvantages:
• Laser can be adversely affected by the bad weather
• Interference from background sources (including sun)
• Laser can affect the eyes
• It is highly expensive

10. What is optical fibre?
• An optical fiber is a flexible, transparent fiber
made of very pure glass (silica) not much
wider than a human hair that acts as a
waveguide, or "light pipe", to transmit light
between the two ends of the fiber . 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 total internal reflection

11. 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.
• Optical Fibre -
An optical fibre is a dielectric wave guide that operates at optical
frequencies. This fibre wave guide is normally cylindrical in form.
• Function -
It confines electro magnetic energy in the form of light to within its
surfaces and guides the light in a direction parallel to its axis.

12. OPTICAL FIBRE IN COMMUNIACTIONS:
• Optical fiber can be used as a medium for telecommunication
and computer 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 little attenuation
compared to electrical cables.
• The per-channel light signals propagating in the fiber have been
modulated at rates as high as 111 gigabits per second (Gbps)
by NTT, although 10 or 40 Gbps is typical.
• In June 2013, researchers demonstrated transmission of 400 Gbps
over a single channel.

13. WORKING:
• The information is passed through
coder and it produces the sequences
of pulses.
• The pulses travel in a light form
through optical fiber
• The optical takes the light to the
detector
• The detector produces output pulses
of light which is transferred to the
decoder
• The decoder converts the information
and passes to the receiver.

14. Advantages:
• In comparison to copper, a fibre optic cable has nearly 4.5 times as much
capacity as the wire cable has and a cross sectional area that is 30 times less
• Since the fibre is a dielectric, it does not present a spark hazard
• Optical fibres are difficult to tap. As they do not radiate electromagnetic
energy, emissions cannot be intercepted
Disadvantages:
• Cables are expensive to install but last longer than copper cables.
• Transmission on optical fibre requires repeating at distance intervals.
• Fibres can be broken or have transmission loses when wrapped around curves
• Optical fibres require more protection around the cable compared to copper.