Lasser communication

LASER COMMUNICATION

NAME: GAURAV SINGH

CONTENT• Introduction• Implementation• Working• Working model• Applications• Advantages• References

Introduction• Laser communication is one of the key area

in wireless Communications. Due to its low noise ratio makes its one of the well suited communication medium for exchange of information.

• Laser communications systems are wireless connection through the atmosphere. Which is focused on decreasing the noise ratio in optical communication system. Laser communications systems work similarly to fiber optic links, except the beam is transmitted through free space.

Working of system

Signal Transmitter Laser

Receiver Signal

Working of system Laser Communication System mainly comprise of 2 sections such as

Transmitter section and Receiver section. Transmitter section is used to transmit the data and sound signals, which

comprised by microphone, Conditioning ckt, analog to digital converter and laser diode to generate medium for transmission of signals.

Transmitter converts the signal into laser beam and transmit it in a straight line.

The receiver section is used to receive the laser beam, using photo transmitter, which incorporated with the data or sound signals from the transmitter comprised of Conditioning, MCR and Digital to Analog converter to extract the data signals from the received laser beam and given as a input to the speaker.

What is the Transmitter?

The transmitter involves: Signal processing electronics (analog/digital) Laser modulator Laser (visible, near visible wavelengths)

What is the Receiver?

The receiver involves: Telescope (referred to as ‘antenna’) Signal processor Detector

-PIN diodes-Avalanche Photo Diodes (APD)-Single or multiple detectors Often both ends will be equipped with a receiver and transmitter

Why Laser Communication?

Current high speed communications technology: Radio Fiber Optics

Laser Link GeometryCritical Design Parameters

Transmit Power

Receive area = 200 cm2

Receiver sensitivityBeam Divergence = 3 mrad

Distance = 1km

Diameter = 3 mBeam area = 70686 cm2

Uplink/Downlink Data Processing Sequence

Bits Bit Encoderto Symbol LASER Transfer

Optics Channel (Atmos.)

Error Correction

Symbol Recovery Amplifier Receiving

OpticsBits

Applications Straight communication with satellite

from the earth.

Tactical Line Of Sight Optical Network (TLSON) uses high frequency laser to transmit data.

One to many communication.

Disadvantages!!Laser link can be affected by- Atmospheric absorption Fog, Rain, Pollution (smoke) Physical obstructions Solar radiations These can be reduced by using Laser tuning, multiple number of transmitters,

filters etc.

Future Scope

It is more secure and provides high bandwidth requirements. The low power consumption is also a great advantage.

It can be the mostly used technique worldwide in near future.