refractive index

American  

noun

Optics.

1. index of refraction.

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refractive index British  

noun

1.  ν.   μ.  physics a measure of the extent to which radiation is refracted on passing through the interface between two media. It is the ratio of the sine of the angle of incidence to the sine of the angle of refraction, which can be shown to be equal to the ratio of the phase speed in the first medium to that in the second. In the case of electromagnetic radiation, esp light, it is usual to give values of the absolute refractive index of a medium, that is for radiation entering the medium from free space

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Etymology

Origin of refractive index

First recorded in 1830–40

Example Sentences

The large change in refractive index allows the formation of extremely fine patterns that remain embedded in the transparent material.

From Science Daily • Apr. 21, 2026

The resulting patterns show strong optical contrast because of the light-induced refractive index changes, making them easy to detect with optical methods.

From Science Daily • Apr. 21, 2026

"Excitons are very sensitive to the charge density in the material, and therefore we can change the refractive index of the material by applying a voltage," says Van de Groep.

From Science Daily • May 30, 2024

To tackle this challenge, researchers are actively exploring nanocomposites, integrating nanoparticles into the resin to boost its refractive index.

From Science Daily • May 9, 2024

At the same time they increase markedly in density and in refractive index and thus become even more snappy and brilliant than when colored.

From A Text-Book of Precious Stones for Jewelers and the Gem-Loving Public by Wade, Frank Bertram