In physics, polarisation can be described as a phenomenon caused because of the nature of the waves of electromagnetic radiation. One common example of electromagnetic waves is the sunlight travelling to the earth through a vacuum. Since these waves form an electric field, they are referred to as electromagnetic waves.
Polarisation is one of the properties of transverse waves associated with the geometrical orientation of their oscillations. In other words, it is the property of transverse waves which tells about the direction of their oscillations. A polarised light wave oscillates only in one direction, while the non-polarised wave can oscillate in multiple directions. The process of transformation of the non-polarised waves into polarised waves is called polarisation.
There are mainly three different types of polarisation. These include –
The first type of polarisation is linear polarisation, where the electric field of the light is only limited to a single plane through the direction of propagation.
In the electric field of light, there are mainly two linear components perpendicular to one another so that their amplitudes are the same. In contrast, their phase is different between two. The occurring electric field’s propagation will be in a circular motion.
The electric field of the light follows the elliptical polarisation. The phase and the amplitude difference between both linear components are not the same.
There are several methods used in light polarisation –
The electromagnetic waves produced by the movement of light through a medium are caused by the vibration of the medium’s atoms (also dust present in the medium). The light is scattered as a result of these waves radiating outward. Light waves are absorbed and re-emitted throughout the entire process. The scattered light is also called partial polarisation, and they cause glare by transmitting partially polarised light.
In the case of unpolarised light falling at a particular angle on a non-metallic surface, the surface reflects the polarised light. To regulate the magnitude of polarisation, angles of incidence and non-metallic surfaces play an important role in this process.
The refraction of light is the act of changing the direction and speed of a light wave as it travels from one medium to another. In doing so, there is polarisation within the refracted beam. Refraction by polarisation is a phenomenon most frequently observed in perpendicular planes.
A filter material with a special chemical composition is used in this method. The filters are called polaroids and block electromagnetic waves on one of their two axes. In a single plane, these polaroid filters let the light that is polarised transmit half of its vibrations. Polarised light has half the intensity.
Some applications of polarisation include the following:
We come to the end of the topic description on polarisation with this. Polarisation can be described as a phenomenon caused because of the nature of the waves of electromagnetic radiation. One common example of electromagnetic waves is the sunlight travelling to the earth through a vacuum. Further, it is classified into three major parts, linear, circular, and elliptical polarisation, which we discussed. Also, a series of methods are used in light polarisation. We ended the topic with a detailed description of electromagnetic waves. We hope it has helped you attain a better understanding of the topic of Polarisation.
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