Törésmutatóértéke

Törésmutatóértéke, often translated as refractive index, is a dimensionless number that describes how light propagates through a medium. It is defined as the ratio of the speed of light in a vacuum to the speed of light in that medium. The symbol for refractive index is typically 'n'.

When light passes from one medium to another with a different refractive index, it bends. This phenomenon is known as refraction and is governed by Snell's Law, which relates the angles of incidence and refraction to the refractive indices of the two media. A higher refractive index means light travels slower in that medium and bends more significantly towards the normal when entering from a lower refractive index medium.

The refractive index of a vacuum is exactly 1 by definition. For all other transparent materials, the refractive index is greater than 1. For example, water has a refractive index of approximately 1.33, and glass typically ranges from 1.5 to 1.7. Diamond has a notably high refractive index of about 2.42.

Refractive index is a fundamental property of optical materials and is crucial in the design of lenses, prisms, and other optical instruments. It also plays a role in understanding phenomena like the dispersion of light, where different wavelengths (colors) of light are refracted at slightly different angles, leading to the separation of colors, as seen in a rainbow. The value of the refractive index can also vary slightly with temperature and the wavelength of light used.