polarisation

• polarisation is when particle oscillations occur in only one of the directions perpendicular to the direction of wave propagation
• polarisation can only occur on transverse waves
• transverse waves oscillate in any plane perpendicular to the propagation direction
• when a transverse wave is polarised, this means that

  • vibrations are restricted to one direction
  • the vibrations are still perpendicular to the direction of energy transfer
• longitudinal waves cannot be polarised as they travel parallel to the direction of propagation
• waves can be polarised through a polariser or polarising filter
• only unpolarised waves can be polarised
• when a polarised wave passes through a filter with a transmission axis perpendicular to the wave, none of the wave will pass through
• when both polarisers have the same transmission axis, the intensity of the transmitted light is at its maximum