Question

Write definitions for plane of vibration and plane of polarization. Explain the working process to obtain the plane polarized light by Nicol prism. Draw the necessary diagram.

Answer 1

Hint: Plane of polarization can be a plane associated with the polarized light wave, while plane of vibration is associated with vibrations of the wave.

Complete step by step answer:
Polarization is the process through which a vibration of a wave along a particular direction is suppressed using a device called the polarizer. The waves along the axis of a polarizer are allowed to pass, while the waves vectors in other directions are blocked or sometimes a polarizer allows vibrations in a certain plane while all other vibrations are blocked.
The plane of polarization is defined as the plane containing the direction of propagation of a polarized wave.
The plane of vibration is the plane which contains vibrations and which is along the optic axis of the wave. It is always perpendicular to the plane of polarization.

Nicol Prism:

A Nicol prism is a type of polarizer, an optical device made from calcite crystal used to produce and analyse plane polarized light. Calcite is a crystal which shows the property of birefringence. Birefringence is the optical property of a material having a refractive index that depends on the polarization and propagation direction of light.
Unpolarized light ray enters through the left face of the crystal, as shown in the diagram, and is split into two orthogonally polarized rays called the ordinary and extraordinary rays which are differently directed rays by the birefringence property of the calcite. The ordinary ray, or o-ray, experiences a refractive index of ${{n}_{o}}=1.658$ in the calcite and undergoes total internal reflection at the calcite–glue interface because its angle of incidence at the glue layer (refractive index n = 1.55) exceeds the critical angle for the interface. It passes out the top side of the upper half of the prism with some refraction. The extraordinary ray, or e-ray, experiences a lower refractive index of ${{n}_{e}}=1.468$ in the calcite and is not totally reflected at the interface because it strikes the interface at a sub-critical angle. The e-ray merely undergoes a slight refraction, or bending, as it passes through the interface into the lower half of the prism. It finally leaves the prism as a ray of plane-polarized light, undergoing another refraction, as it exits the far right side of the prism.

Note: Transverse waves and Transverse longitudinal waves show polarization properties, while ordinary longitudinal waves other than transverse longitudinal waves do not show polarization.
In linear polarization, the fields oscillate in a single direction. In circular or elliptical polarization, the fields rotate at a constant rate in a plane as the wave travels. The rotation can have two possible directions; if the fields rotate in a right hand sense with respect to the direction of wave travel, it is called right circular polarization, while if the fields rotate in a left hand sense, it is called left circular polarization.