Wednesday, 30 September 2015
Glittering crystals in the wood of Larix decidua
Linearly polarized light or planar polarized light, is polarized light that consists of light waves that vibrate only in one direction (or in other words, only in one plane) In nature it is the most common kind of polarized light. Linearly polarized light occurs, for example, by scattering of light in the atmosphere or by reflection of light on a water surface. Linearly polarized light is used in the optics in polarization microscopes.
A polarizing microscope is a microscope wherein the object is located in the optical path between two polarizing filters. It is thus illuminated, or irradiated with polarized light. In the optical system of the microscope also a rotatable polarizing filter is included. If the object itself rotates the polarization direction of the light, this can be detected by the microscopist. If he puts the two polarization filters in a crossed state with each other, then normally no more light will be transmitted from the light source to the eye, except when the object itself is optically active, then it will light up clearly, sometimes in striking rainbow colors. This is of particular importance in distinguishing different crystals and minerals.