Rohan Ece 42 Free Space Laser Communication
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Transcript of Rohan Ece 42 Free Space Laser Communication
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FREE SPACE LASER
COMMUNICATIONPRESENTED BY :
ROHAN BHATNAGAR
ECE VIIITH SEM
07EAYEC042
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TALK FLOW
Basic overview
System overview
Introduction
Multi- path laser communicationAdvantages
Disadvantages
Security aspects
Safety aspects
Application
Conclusion2/18
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WHAT IS FREE-SPACE LASER
COMMUNICATION
Data is transmitted by modulated laser light
where the laser beam travels through the
atmosphere.
Its a wireless connection through the
atmosphere.
The laser light across the link is at a
wavelength of between 780-920nm.
Two parallel beams are used, one for
transmission and one for reception.(4/18)
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BASIC OVERVIEW OF FREE SPACE
LASER COMMUNICATION
Runs in infrared spectrum.
Optical signal is in the range of THz
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SYSTEM OVERVIEW OF FREE
SPACE LASER COMMUNICATION
The system consists of two transceivers, each
capable of simultaneously transmitting &
receiving either analogue or digital
information.
User selects between either analogue or
digital information via means of two switches.
In normal operation, the system is a full
duplex analogue/digital communicator.
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HARDWARE:
It is divided into two main categories:
The analogue transceiver-including VU
meter.
The digital transceiver.
The design incorporates three circuits
which perform analogue modulation,
digital modulation, and signal strength
display.
The completed system houses all these
modules as a single unit, sharing the
critical input & output components. 8
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FREE SPACE MULTI-PATH LASER
COMMUNICATION SYSTEMS:All laser beams hit the target point(optics &
photo-diode of the receiver)coherently.
This is achieved by phase control analogcircuit.
ADVANTAGES OF MULTI-PATH LASERCOMMUNICATION SYSTEMS:
Robustness in performance(not all beams areinterrupted simultaneously).
Better safety.
Easier design and built of stable lasersources and optics.
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THE DEGRADATION EFFECTS
CAN BE CATEGORIZED AS:Propagation effect:
Due to presence of heavy fog, snow or smoke
blocks the line-of-sight between the units.
Sun is interfering the laser beam.
Mechanical insufficiencies:
As the optical beam is narrow, the link
performance is sensitive to vibration, wind
sway, and thermal expansion of the
equipment.11
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ADVANTAGES:
Eliminates the need of buried cable installations. No need of Govt. licensing.
No spectrum fees have to be paid.
No radio interference.
Systems are quickly deployable.
High data rate & security.
More highly directional then RF communication.
Extremely high bandwidth.
Large information throughput that is many times
greater than RF communication. Small antenna size.
One third in mass.
Half in power requirement.
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APPLICATIONS:
Transmission of digital computer data
(LAN interconnect) video, voice,
multiplexed data etc.
Provides bitrates up to 1.25 Gbps at
shorter distances.
Suitable for temporary connectivity needs
such as at conventions, sporting events,corporate & university campuses, militaryoperations etc.
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CONCLUSION:
Laser-com technology on path to be operationallyfielded in space in next decade
Revolutionary increases in capability andreductions in size ,weight & power.
Telecom-like interoperability standards shouldhelp keep costs down.
Continued R & D to achieve ultimate potential
Laser-com to/from aircraftMultiple users per terminal(multi-access)
Advanced technology for high sensitivity and highdata rates.
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