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Lasers in communication
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Coherent light carries data at high rates.
Lasers produce coherent narrow-band light that can be modulated at GHz rates for fibre links and satellite-to-ground links.
Laser links to the Moon transmit video.
Atmospheric turbulence is an issue.
In more detail
Lasers emit coherent light of a single wavelength, which can carry information when modulated. Laser communication is used over fibres and in free-space links.
Real-world uses
- Fibre optic systems use lasers as transmitters.
- Free-space laser links connect satellites and aircraft.
- Fibre-optic networks use laser light, which is coherent and narrow in wavelength, to carry data over long distances.
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Frequently asked questions
Why are lasers used?
They are narrow and coherent, so they can carry data at high rates.
Do lasers need fibre?
No. Free-space optical links transmit through air or vacuum.
Why are lasers used for data?
They produce a narrow, focused beam that can be modulated quickly, so more data can be packed into each pulse.
Related topics in AC Circuits & EM Waves
Modulation (AM and FM) · Optical fibre communication · Radar · Electromagnetic shielding · Skin effect · Resonant cavities