what is polarisation of light?

Question

plane of polarisation

Answer 1

Polarisation of Transverse Waves
We can classify waves into 2 types:

1. Longitudinal: the thing that is waving is in the same direction as the velocity of the wave. Examples include sound waves and a wave traveling down a slinky. A Flash animation of a sound wave -- - the thing that is waving, the air molecules, are oscillating in the same direction as the wave velocity.
2. Transverse: the thing that is waving is perpendicular to the velocity of the wave. Examples include water waves and waves on a string. It turns out that light is a transverse wave of electric and magnetic fields. A Flash animation of a light wave -- - that the electric and magnetic fields are perpendicular to each other and to the direction of motion of the wave.
A moment's reflection will convince you that a transverse wave can have the plane of the oscillation at different orientations. The plane is called the polarisation of the wave Polaroid filters are capable of selecting a particular polarisation state from an incident light wave. By convention the polarisation of a light wave is specified by the orientation of the electric field.
Edwin Land, a Harvard dropout, invented the polaroid filters, in 1926. Before then the main way of producing a polarised beam of light was using a property of reflected light.

The electric and magnetic fields are always at right angles to each other in an electromagnetic wave. By convention, the direction of polarisation of the light is taken to be the direction of the electric field vector.
At a single point in space, the electric field vector can only point in one direction at a time. If it maintains the same orientation along the wave, the wave is plane polarised. If the field vector rotates along the wave, then the wave is circularly (or elliptically) polarised.
VR

Answer 2

The light is like a helix travelling longitudinally (along the helix axis). The light intensity is described as a vector (perpendicular to the axis) from the axis to the edge of a helix. Now, if you imagine steady plane perpendicular to the helix the light vector will rotate 360 degrees while the light is traveling through the plane. If you make a plane opaque the light will not go through. Now, if you make the straight cut in the shape of long narrow rectangle the light will go through but only vectors that are parallel with the rectangle. (The plane made out of axis and longer side of the rectangle is called plane of polarization.) This light is of less intensity and polarized in the direction of the rectangle. If you put another plane with the narrow rectangle perpendicular to the first one the light will not go through since it was polarized by the first rectangle.

Answer 3

"The electric and magnetic fields are always at right angles to each other in an electromagnetic wave. By convention, the direction of polarization of the light is taken to be the direction of the electric field vector.

At a single point in space, the electric field vector can only point in one direction at a time. If it maintains the same orientation along the wave, the wave is plane polarized. If the field vector rotates along the wave, then the wave is circularly (or elliptically) polarized."


when light strikes a pool of water for example, there is a certain angle that which light is polarized... the plane of polarization is the plane of the water surface.... after being polarized by reflection, light comes to our eyes, very glaring... that's why we wear polarize rs (glasses) such that the orientation of the polarize is perpendicular to the polarized light.... (vertical is the glass polarizer orientation because polarized light is oriented horizontally)....

Answer 4

Different colors of light refract at different angles. The plane along which a light of certain color refracts is the plane of polarisation.