kokonaisheijastuvuus

Kokonaisheijastuvuus, also known as total internal reflection in English, is an optical phenomenon that occurs when a light ray travels from a denser medium to a less dense medium and strikes the boundary between the two media at an angle greater than the critical angle. When this condition is met, the light ray does not refract into the less dense medium but is instead entirely reflected back into the denser medium.

The critical angle depends on the refractive indices of the two media. It is the angle of incidence for which the angle of refraction is 90 degrees. If the angle of incidence exceeds this critical angle, total internal reflection occurs. This phenomenon is fundamental to the operation of fiber optics, where light signals are guided along optical fibers through repeated total internal reflections.

Other applications of kokonaisheijastuvuus include prisms in binoculars and periscopes, where they are used to redirect light. Diamonds exhibit a high degree of brilliance partly due to total internal reflection, as their high refractive index leads to a small critical angle, causing most of the light entering the diamond to be reflected internally. Understanding kokonaisheijastuvuus is crucial in fields such as optics, telecommunications, and materials science.