A ray of light being refracted in a plastic block
A triangular prism dispersing a beam of white light. The longer wavelengths (red) and the shorter wavelengths (blue) are separated.
The reflection of Mount Hood in Mirror Lake.
Refraction of a light ray
The electromagnetic spectrum, with the visible portion highlighted
Diagram of specular reflection
Thomas Young coined the term index of refraction.
Refraction of light at the interface between two media.
Diamonds have a very high refractive index of 2.417.
Beam of sun light inside the cavity of Rocca ill'Abissu at Fondachelli-Fantina, Sicily
An example of the law of reflection
A split-ring resonator array arranged to produce a negative index of refraction for microwaves
Due to refraction, the straw dipped in water appears bent and the ruler scale compressed when viewed from a shallow angle.
General scattering mechanism which gives diffuse reflection by a solid surface
In optical mineralogy, thin sections are used to study rocks. The method is based on the distinct refractive indices of different minerals.
Hong Kong illuminated by colourful artificial lighting.
Working principle of a corner reflector
Light of different colors has slightly different refractive indices in water and therefore shows up at different positions in the rainbow.
Pierre Gassendi.
Multiple reflections in two plane mirrors at a 60° angle.
In a prism, dispersion causes different colors to refract at different angles, splitting white light into a rainbow of colors.
Christiaan Huygens.
Sound diffusion panel for high frequencies
The variation of refractive index with wavelength for various glasses. The shaded zone indicates the range of visible light.
Thomas Young's sketch of a double-slit experiment showing diffraction. Young's experiments supported the theory that light consists of waves.
The colors of a soap bubble are determined by the optical path length through the thin soap film in a phenomenon called thin-film interference.
Refraction of light at the interface between two media of different refractive indices, with n2 > n1. Since the phase velocity is lower in the second medium (v2 < v1), the angle of refraction θ2 is less than the angle of incidence θ1; that is, the ray in the higher-index medium is closer to the normal.
Total internal reflection can be seen at the air-water boundary.
The power of a magnifying glass is determined by the shape and refractive index of the lens.
The relation between the refractive index and the density of silicate and borosilicate glasses
A calcite crystal laid upon a paper with some letters showing double refraction
Birefringent materials can give rise to colors when placed between crossed polarizers. This is the basis for photoelasticity.
A gradient-index lens with a parabolic variation of refractive index (n) with radial distance (x). The lens focuses light in the same way as a conventional lens.
The principle of many refractometers
A handheld refractometer used to measure the sugar content of fruits
A differential interference contrast microscopy image of yeast cells

In optics, the refractive index ( refraction index) of an optical medium is a dimensionless number that gives the indication of the light bending ability of that medium.

- Refractive index

Common examples include the reflection of light, sound and water waves.

- Reflection (physics)

In fact, reflection of light may occur whenever light travels from a medium of a given refractive index into a medium with a different refractive index.

- Reflection (physics)

where θ1 is the angle between the ray and the surface normal in the first medium, θ2 is the angle between the ray and the surface normal in the second medium and n1 and n2 are the indices of refraction, n = 1 in a vacuum and n > 1 in a transparent substance.

- Light

Apart from the transmitted light there is also a reflected part.

- Refractive index

Newton's theory could be used to predict the reflection of light, but could only explain refraction by incorrectly assuming that light accelerated upon entering a denser medium because the gravitational pull was greater.

- Light
A ray of light being refracted in a plastic block

0 related topics with Alpha