it is usefull for laser communication system

1. CAUVERY INSTITUTE OF TECHNOLOGY
MANDYA
VISVESVARAYA TECHNOLOGICAL UNIVERSITY
A Technical Seminar Presentation
On
“Laser Communication System”
Under the guidance of
Prof. Anitha H C
Associate professor
Presenting by:
NIKHIL N - 4CA20EC008
Department of Electronics & Communication
Engineering
2023-2024

2. Contents:
• Introduction
• How does Laser Communication Work?
• Laser transmitter and receiver
• Modulation
• Filters
• Application
• Advantages
• Disadvantages
• Conclusion
• Reference
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3. Introduction
• Laser communications systems are wireless connections through the
atmosphere.
• They work similarly to fiber optic links, except the beam is transmitted
through free space.
• While the transmitter and receiver must require line-of-sight conditions,
they have the benefit of eliminating the need for broadcast rights and
buried cables.
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4. Laser Transmitter and Receiver
Laser Transmitter Receiver
Optical fiber link
Direct Link
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5. Laser Transmitter:
• The Transmitter involves a signal processing
circuit, and a laser.
• A laser diode is used to create the laser signal.
• Laser Diodes include Photodiodes for feedback
to insure consistent output.
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6. Receiver
The receiver involves:
• Telescope(‘antenna’)
• Signal processor
• Detector
 PIN diodes
 Avalanche Photo Diodes(APD)
 Single or multiple detectors
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7. Modulation:
• AM
Easy with gas lasers, hard with diodes
• PWM (pulse width modulation)
Used by Ramsey in their kit
• PFM(pulsed Fm)
Potentially the highest bandwidth (>100khz)
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8. Filters:
• Sun shade over detector
• Shade in front of lens
• Detector spectral response
• Colored filters
• Absorb 50% of available light
• Difficult to find exact frequency
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9. Applications:
• Transmit voice for miles line-of-sight.
• Use weak signal modes for Cloud scatter.
• Transmit video with cheap pens.
• Transmit high speed data without WEP.
• Blind flies for easy extermination.
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10. Advantages:
• Ease of deployment
• Can be used to power devices
• License-free long-range operation (in contrast with radio communication)
• High bit rates
• Low bit error rates
• Immunity to electromagnetic interference
• Protocol transparency
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11. Disadvantages:
For terrestrial applications, the principal limiting factors are:
• Beam dispersion
• Atmospheric absorption
• Rain
• Fog (10 -100 dB/km attenuation)
• Snow
• Interference from background light sources (including the Sun)
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12. Conclusion:
• Laser communications offers a viable alternative to RF communications for inter
satellite links and other applications where high-performance links are a
necessity.
• High data rate, small antenna size, narrow beam divergence, and a narrow field
of view are characteristics of laser communications that offer a number of
potential advantages for system design.
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13. References:
1. Sadiku, M. N. O., Musa, S., & Nelatury, S. R. (2021). Free space
optical communications: an overview. European scientific journal,
ESJ, 12(9), 55.
2. Prof. Atul A. Padghan | prof. Ankit P. Jaiswal" study on laser
communication: features, application, advantages" published in
international journal of trend in scientific research and development
(ijtsrd), ISSN: 2456-6470, volume-2 | issue3, April 2019
3. (2020, December 23). Laser communication space.
Https://ivypanda.Com/essays/ laser-communication-links-in-space
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14. Thank You
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