Etienne Malus was the one who discovered polarization back in 1808. The law that is credited to her, the Malus law states that when light passes through an ideal polarizer, the intensity of light will have a value of cos2 θ, theta being the angle of the light source (“Polarization”). In 1920s, Edwin Land is the inventor of the first polarizer (“Polarization”). He also founded the Polaroid company. This was made possible because of the Herapathite crystals, which are needle-like, aligned on a film producing a polarizer. The polarized light that is parallel to the crystals are absorbed, the ones who are perpendicular are transmitted (“Polarization”).
In general, there are two types of polarization: linear and circular (“Polarization”; Reichmann). Sometimes, an elliptical polarization is included. Linear polarization involves either only vertical, horizontal, or an angle that is between zero to π/2. Almost all antennas use this kind of polarization. With circular polarization, the electromagnetic waves are broken into two parts that are 90˚ apart from each other. When one of these components moved, the other will rotate to maintain the 90˚ between them. The movement called the phase shift can be to the left or to the right. It can be left handed polarization (LCP) or right handed polarization (RCP). An example of this is a communication link which the angle of the receiver with respect to the transmitter doesn’t matter for the wave will just spin inside (“Polarization”). The third one, the elliptical polarization is the result when the angle between the two components of circular polarization is not exactly 90˚. There will be a ratio between the amplitudes and this is the axial ratio (“Polarization”).
Polarizers are developed for they have the ability to block light and just let the needed light to pass through. These serve as a filter in terms of light experiments. Nowadays, polarizers can be made with a number of ways. Polaroid, one of the most common of them, is used with iodine crystals that are embedded in a polymer (NISE). Polarizers are used with anything that has to do with light. These can be displays, lens in the glasses, telescopes, even the 3D glasses that you’ve worn when you watched a 3D movie (NISE). They are also used in the camera lenses in photography. It helps the photographer filter out the light that is unnecessary in the photo, thus, making it as a very important part of a photographer’s kit (Reichmann).
Works Cited
“Polarization.” Microwaves101. Web. 04 Apr. 2016. <http://www.microwaves101.com/encyclopedias/polarization>.
National Informal Science Education Network. “Polarization.” Microwaves101. Web. 04 Apr. 2016. <http://www.microwaves101.com/encyclopedias/polarization>.
Reichmann, Michael. “Polarizers - Luminous Landscape.” Luminous Landscape. 31 Mar. 2011. Web. 04 Apr. 2016. <https://luminous-landscape.com/polarizers/>.
