Explain the phenomenon of polarization
The phenomenon of interference and diffraction have proved that light has wave nature, but these phenomena do not show whether light’ waves are longitudinal or transverse. The phenomenon of polarization shows that light ‘waves are transverse. Transverse mechanical waves, the vibration can be oriented along vertical, horizontal or any other direction, in each of these cases, the wave is said to be polarized. The plane Of polari>atioh is-the pine containing the direction of vibration of the particles of the medium and the direction of propagation of Wove. A light wave produced by oscillating charge consists of a periodic variation of electric field vector along with magnetic field-vector at a right angle to each other. The direction of polarization in a plane polarized -light wave is taken, asl the direction Of electric field vector.
A beam of ordinary light consisting of a large number of planes of vibration is called unpolarized light.
Thé has been of light in which all vibrations are confined •to a single’ plane of vibr.tion is called Polarized light. Production and Detection of aircraft polarized light.
The light emitted by an ordinary incandescent bulb is unpolarized, because its vibrations are randomly oriented in space. It is possible to obtain a plane polarized beam of light from unpolarized light by removing all waves from the beam except those having vibrations along one particular direction. This can be achieved by a various method as given below:
Selective absorption Reflection from different surfaces. Scattering by small particles Refraction the augh crystals.
Selective absorption method:
Particular abortion method is the most common method to obtain plane polarized light by using certain types of materials called dichroic substances. These transmit only those waves, whose Vibration are parallel. To’ the particular, direction and will absorb those waves whose that strong vibration is in other courses. One such commercial polarizing material vibrations is Polaroid. If the un-polarized light is made incident on thé sheet of Polaroid, the transmitted light will be Élane polarized. If the second sheet of Polaroid is placed in such a way that the axes of the Polaroid, as shown by the straight lines drawn on them, are parallel, the waves is transmitted through the second Polaroid also.