What Are Polarized Light?
A light wave is an electromagnetic wave that travels through the vacuum of outer space. Light waves are produced by vibrating electric charges. More importantly, light waves are transverse, that is, the vibrating electric vector associated with each wave is perpendicular to the direction of propagation. Polarized light waves are light waves in which the vibrations occur in a single plane. Plane polarized light consists of waves in which the direction of vibration is the same for all waves. Intensity of polarized light depends on the nature of the polaroid used. A Polaroid filter is able to polarize light because of the chemical composition of the filter material. The process of transforming unpolarized light into polarized light is referred to as polarization.
There are a variety of methods of polarizing light i.e
- Transmission
- Reflection
- Refraction
- Scattering
Facts About Polarized Light
- Polarized light means restricting the vibration of the light particles in a single plane.
- Polarized light has electric fields oscillating in one direction.
- Polarized light is coherent in nature.
- Intensity of polarized light depends on the nature of the polaroid used. A Polaroid filter is able to polarize light because of the chemical composition of the filter material.
- For polarized light, the x-and y-components of the electric field has a constant phase difference between them.
- Light produced by natural sources are always polarized.
What Unpolarized Light?
A light wave that is vibrating in more than one plane is referred to as Unpolarized light. Light emitted by the sun, by lamp in the classroom or a by a candle flame is unpolarized light. Such light waves are created by electric charges that vibrate in a variety of directions, thus creating an electromagnetic wave that vibrates in a variety of directions.
Facts About Unpolarized Light
- Unpolarized light means the lighting is not having vibration restricted in a single plane.
- Unpolarized light has electric field oscillating in all directions.
- Unpolarized light is incoherent in nature.
- The intensity of unpolarized light depends on the nature of source.
- In Unpolarized light, the phase difference between the x-and y-components of the electric field changes unpredictably.
- Unpolarized light can be produced when Unpolarized light undergoes reflection, scattering or travels through a material that can cause polarization.
Also Read: Difference Between Light And Sound Waves
Difference Between Polarized And Unpolarized Light In Tabular Form
| BASIS OF COMPARISON | POLARIZED | UNPOLARIZED LIGHT |
| Description | Polarized light means restricting the vibration of the light particles in a single plane. | Unpolarized light means the lighting is not having vibration restricted in a single plane. |
| Electric Fields | Polarized light has electric fields oscillating in one direction. | Unpolarized light has electric field oscillating in all directions. |
| Nature | Polarized light is coherent in nature. | Unpolarized light is incoherent in nature. |
| Nature | Intensity of polarized light depends on the nature of the polarizer used. | The intensity of unpolarized light depends on the nature of source. |
| Phase Component | For polarized light, the x-and y-components of the electric field has a constant phase difference between them. | In Unpolarized light, the phase difference between the x-and y-components of the electric field changes unpredictably. |
| Production | Light produced by natural sources are always polarized. | Unpolarized light can be produced when Unpolarized light undergoes reflection, scattering or travels through a material that can cause polarization. |
Also Read: Difference Between Interference And Diffraction Of Light
Applications Of Polarization
- Polarization is used in sunglasses to reduce the glare.
- Polaroid filters are used in plastic industries for performing stress analysis test.
- Three-dimensional movies are produced and shown with the help of polarization.
- Polarization is used for differentiating between transverse and longitudinal waves.
- Infrared spectroscopy uses polarization.
- It is used in seismology to study earthquakes
- In chemistry, the chirality of organic compounds is tested using polarization techniques.
Also Read: Difference Between Fresnel And Fraunhofer Diffraction