index of refraction

American  

noun

Optics.

1. a number indicating the speed of light in a given medium as either the ratio of the speed of light in a vacuum to that in the given medium absolute index of refraction or the ratio of the speed of light in a specified medium to that in the given medium relative index of refraction. n

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index of refraction British  

noun

1. another name for refractive index

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index of refraction Scientific  

1. A measure of the extent to which a substance slows down light waves passing through it. The index of refraction of a substance is equal to the ratio of the velocity of light in a vacuum to its speed in that substance. Its value determines the extent to which light is refracted when entering or leaving the substance.

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Etymology

Origin of index of refraction

First recorded in 1820–30

Example Sentences

See Examples For:

index of refraction

The difference in index of refraction between the two materials defines the angle of that bending.

From Scientific American ● Nov. 18, 2022

Light entering a medium with a negative index of refraction, on the contrary, would bend backward, creating unexpected optical effects, such as a straw appearing to lean the wrong way.

From Scientific American ● Nov. 18, 2022

Figure 25.15 Fibers in bundles are clad by a material that has a lower index of refraction than the core to ensure total internal reflection, even when fibers are in contact with one another.

From Textbooks ● Aug. 12, 2015

We know that the index of refraction n depends on the medium.

From Textbooks ● Aug. 12, 2015

It is a curious property of this vibrational system of invisibility that the index of refraction is made very low.

From The Black Star Passes by John Wood Campbell