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Polarisation of EM waves
Intermediate
The E field oscillates in a particular direction.
Polarisation is the orientation of E: linear, circular or elliptical. Polarising sunglasses block horizontally polarised glare.
Radio antennas need matching polarisation.
Transverse waves only.
In more detail
Polarisation describes the direction in which the electric field of a transverse wave oscillates. Polarisers pass only one direction, and reflection can partially polarise light.
Real-world uses
- Polarising sunglasses reduce glare from reflected light.
- LCD screens use polarised light to display images.
- Polarised sunglasses reduce glare because they block light whose electric field oscillates in one direction.
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Frequently asked questions
Can sound be polarised?
No. Longitudinal waves cannot be polarised.
How does a polariser work?
It transmits only the component of the field parallel to its axis.
What is polarisation?
The orientation of the electric field in a transverse wave, which can be fixed in one direction for polarised light.
Related topics in AC Circuits & EM Waves
Ultraviolet · X-rays · Gamma rays · Antennas · Waveguides and transmission lines · Modulation (AM and FM)