polarisatsioonijoonte

Polarisatsioonijoonte, or polarization lines, are a phenomenon observed in certain optical materials and experimental setups. They relate to the direction of polarization of light. When light passes through a material with anisotropic properties, such as certain crystals or stressed polymers, its polarization state can be altered. This alteration can lead to the appearance of lines or patterns that indicate the orientation of the electric field vector of the light.

These lines are often visualized by using polarizers. A polarizer is a filter that allows light waves vibrating in a specific plane to pass through. If polarized light passes through a second polarizer, known as an analyzer, its intensity will depend on the relative orientation of the two polarizers. When the polarization of the light is aligned with the transmission axis of the analyzer, maximum light is transmitted. Conversely, when the polarization is perpendicular to the analyzer's axis, minimal or no light passes through.

In materials exhibiting stress-induced birefringence, for example, internal stresses cause the material to behave differently for light polarized along different axes. When viewed between crossed polarizers (where the transmission axes are perpendicular), these differences in refractive index for different polarization directions become visible as colored or dark lines. These lines, the polarisatsioonijoonte, reveal the distribution and magnitude of the internal stresses within the material. This technique is widely used in engineering and materials science for stress analysis and understanding material behavior.