Polarized light microscopy
In polarized light microscopy, two polarization filters are introduced into the beam path. The polarizer converts white light (as a mixture of all polarization directions) into linearly polarized light.
If an analyzer with 90° orientation with respect to the polarizer is used (crossed polarizers), only light can reach the camera, which has changed its polarization direction upon interaction with the sample. In this image contrast, amorphous parts of the sample appear dark, whereas the contrast of, e.g., certain crystals and small particles is enhanced, which can change the light polarization due to birefringence or light scattering, respectively.