Polarisation
Polarisation refers to the process by which light is restricted to a particular direction of oscillation. Natural light oscillates in all possible directions perpendicular to the direction of propagation. In polarised light, by contrast, these oscillations are reduced to a single plane. This effect can be achieved by various methods, such as the use of polarising filters or by reflection.
In the field of morphology, particularly in the microscopic examination of thin tissue sections prepared with a microtome, polarisation plays an important role. Through the use of polarised light, certain structural details of the samples can be made more visible that would be difficult to discern under normal light.
This is particularly useful in the examination of anisotropic materials, which exhibit different optical properties in different directions. Polarised light can help to emphasise these differences and thus enable a more precise analysis of the microscopic structure.