What is the polarization of light?

If you look at the sky in the autumn cloudless day, then the radiant blue sky dome will not leave anyone indifferent. What explains this amazing color? Its cause lies in three aspects - refraction, dispersion and polarization. In today's work we will talk about what is the polarization of light.

Light is one of the varieties of electromagnetic radiation, therefore it is characterized by its source and direction. In addition, one should not forget about its dual nature: in one case, as it was already said, it represents a wave, and in another it is a particle (photon). Polarization of light is one of the properties of any radiation in the optical range. In the case of polarization, the oscillations of the light beam particles directed to the transverse surface are realized in the same plane. Other components are cut off.

The easiest way to understand by an example is the polarization of light. Imagine a long rope, located horizontally between two points. The rope passes through a vertical slot in the shield plate. If now it is picked up from one end and waves formed, then they will reach the opposite end only if they are created coaxially with a slot in the shield, i.e. Vertically. When you try to move the rope horizontally (left-right), the waves will be extinguished, barely reaching the shield, as they do not "squeeze" across the slit. In this example, the rope is electromagnetic radiation, the shield is a transparent (or semitransparent medium), and the slit is a specific property of the medium.

Since light is an electromagnetic wave, it depends on the electric and magnetic vectors of tension. They are always perpendicular to each other and, in addition, form a conditional plane perpendicular to the propagation lines of the wave itself. By the way, circular polarization of light arises in the case when the vectors of magnetic induction and electric field rotate relative to the direction of the light beam. In turn, with vibrations of the electric field strength vector in the same plane, a plane-polarized electromagnetic wave arises. Its second name, reflecting the same process is "linearly polarized."

It is interesting that the emission by an atom of a single quantum of light is always polarized. At the same time, the light flux of a light bulb, the sun, a candle, a flashlight, etc., is unpolarized. This is due to the fact that the radiation comes from a multitude of atoms in which the polarization is different. Accordingly, the total flow loses focus. The polarization of light depends to a great extent on the characteristics of the substance or the arrangement of atoms in its crystal lattice (for solids, for example, transparent crystals). By the way, the first experiments were performed with crystals and only afterwards scientists paid attention to gaseous media (atmosphere). It is not difficult to understand that the polarization of light also depends on the location of the observer (sensor, photocell, etc.). Thus, with increasing angle between the direction of light from the source and the vector indicating the direction of the line of sight, the polarization increases. If the directions are parallel, then under ideal conditions there is no polarization.

There is also a third option - a partially polarized light stream. This configuration occurs when the electric field or magnetic induction oscillations predominate (their vectors).

Curious fact: the human eye easily distinguishes the wavelength (color aspect of light) and intensity, but the registration of polarization is available indirectly. At the same time, many insects with faceted eyes perfectly distinguish the polarization of the wave. It is believed that this helps them navigate.