1. Common examples:- Sound, slinky springs seismic p waves
Longitudinal Waves
Direction of travel
VIBRATION
The direction of vibration of the particles is parallel to the direction in which the wave travels.
Common examples:- Sound, slinky springs seismic p waves
Longitudinal waves cannot be polarised
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2. Common examples:- Water, electromagnetic, ropes, seismic s waves
Transverse
Direction of travel
vibration
The direction of vibration of the particles is perpendicular to the direction in which the wave travels.
Common examples:- Water, electromagnetic, ropes, seismic s waves
You can prove that you have a transverse wave if you can polarise the wave (especially important with light (electromagnetic) as you cannot “see” the wave!!)
John Parkinson

3. Electric vector E
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Magnetic vector B

4. Electric vector E
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Magnetic vector B

5. P O L A R I S T N
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6. P O L A R I S T N
(polariser)
(analyser)
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7. P O L A R I S T N (polariser) (analyser) Resolved component
of electric vector
is un-polarised
(analyser)
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8. is vertically plane polarised
(polariser)
(analyser)
Electric vector
is un-polarised
Electric vector
is vertically plane polarised
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9. P O L A R I S T N (polariser) (analyser)
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Transverse waves are plane polarised if the vibrations occur in one plane only.

10. Uses of polarisation
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14. Using polarisation to measure concentration
laser
polariser
Analyser
Rotated to allow
minimum transmission
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15. Using polarisation to measure concentration
Sugar
solution
laser
analyser
polariser
Some liquids are ‘optically active’ and rotate the electric vector.
The liquid’s concentration is proportional to the electric vector rotation.
John Parkinson

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