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

See Examples For:

refractive index

That additional interaction time amplified the small refractive index change in the silicon.

From Science Daily ● Sep. 18, 2026

When materials undergo these phase changes, important physical properties can change as well, including density and refractive index, which affect how sound and light travel through them.

From Science Daily ● Aug. 22, 2026

This effect, known as photorefractivity, occurs when exposure to light alters the refractive index.

From Science Daily ● Apr. 21, 2026

By comparing the patterns in forward- and back-scattered light, they could estimate each particle's size and its refractive index, which describes how strongly light bends or scatters when it passes through a material.

From Science Daily ● Nov. 17, 2025

Homogeneity.—The optical desideratum is uniformity of refractive index and dispersive power throughout the mass of the glass.

From Encyclopaedia Britannica, 11th Edition, Volume 12, Slice 1 "Gichtel, Johann" to "Glory" by Various