1809 made its changes in the scientific world society.Engineer from France E. Malus discovered a new way to light polarization.Through experiments, he accidentally drew attention to the fact that if the crystal is rotated around the beam reflected from the glass, the light intensity can periodically both increase and decrease.But all the light does not go out, but only reinforced or weakened, but only at a certain position a crystal.The statement has been called "the law of Malus," it has been recognized in the scientific community.
From physics we know that light can be converted to plane-polarized beam.This occurs when using special devices that can allow only a certain direction fluctuations.Examples include being parallel to the vibrations transmitted light and perpendicular delaying fluctuations.As a polarizer used anisotropic medium with respect to vibration vector, such as crystals.The most famous of natural origin is tourmaline.It is quite strongly absorbs light rays that its electric vector perpendicular to the visual axis, which also follows as a conclusion of law Malus.But the light in which it is parallel, almost absorbed.This explains the fact that natural light passing through the crystal plate, is absorbed by half and is polarized with the electric vector of linearly arranged parallel to the visual axis of tourmaline.
easier to handle crystal has exactly the same properties as a polaroid.It consists of artificially prepared colloidal films, which are needed in order to obtain polarized light.As with tourmaline, the principle of operation is based on a single chip, which absorbs vibrations perpendicular to the direction of light.And this phenomenon is not expressed in the law of Malus.Consider another example.
But when the polarization of light rays occurs when refraction or reflection on the border with isotropic dielectric - it is the law of Malus.He corrected a few physical phenomena associated with the electrical oscillations of light.
But the law of Malus, the conclusion is stated above, does not claim that such a method of polarization of the primary and sole.There are others.
Any device used for polar light rays is called a polarizer.But it is studied and researched with the help of the analyzer.
example, there are two chips, which are arranged one behind the other so that the axes form an angle.Origin miss light whose electric vector is directed parallel to its axis.The component of the intensity of the beam will be delayed a second crystal.And after two polaroid it will be the same length of the electric vector.In other words, the ratio of these intensities is proportional to the square of the amplitude.
We conclude that the light transmitted through the analyzer at its output beam power is en route through a polarizer and multiplied by the cosine squared of the angle between them.This relation is a phenomenon that describes the law of Malus.
This also can be attributed to the double refraction of light, which is the main feature when passing through crystals.This is due to the features that are present in the environment anizatropa the propagation of light.For example, sending a crystal spar narrow light beam passing through it, there will be two separate beams that are parallel to each other.This will occur in any case, even if the light incident on the crystal in its normal position.One of them is called the ordinary and is a continuation of the primary beam, and the second - an extraordinary, as has the ability to deviations.
