Polarsichtmikroskopie

Polarsichtmikroskopie, also known as polarization microscopy or polarized light microscopy, is a type of optical microscopy that utilizes polarized light to study the optical properties of specimens. This technique is particularly useful for examining anisotropic materials, which exhibit different optical properties when viewed from different directions. These materials include crystalline substances, such as minerals and synthetic polymers, as well as biological structures like muscle fibers and cell walls.

In a polarization microscope, two polarizing filters are employed. The first polarizer, called the polarizer, is placed below the specimen and filters the incoming light, allowing only light waves vibrating in a specific direction to pass through. The second polarizer, the analyzer, is positioned above the specimen and is oriented perpendicular to the polarizer. When no specimen is present, or if the specimen is isotropic and does not alter the polarization of light, the analyzer blocks all light, resulting in a dark field of view.

However, when an anisotropic specimen is placed in the light path, it can rotate the plane of polarization of the light passing through it. If the specimen's orientation relative to the polarizers is such that it changes the polarization, some light will be able to pass through the analyzer, making the specimen visible against the dark background. Different anisotropic materials will interact with polarized light in unique ways, producing characteristic colors (interference colors) and brightness variations when viewed through crossed polarizers. These differences allow for the identification and characterization of minerals, the study of stress in transparent materials, and the investigation of the structure of biological samples.