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

The ensemble was excited by a linearly polarized green laser with a wavelength of 532 nanometers, and a high refractive index hemispherical lens was used to enhance the collection efficiency of the laser-induced fluorescence.

From Science Daily ● Jun. 6, 2024

This plate is almost transparent to the terahertz rays, but it has a higher refractive index than the surrounding air, so at each point of the plate, it changes the incident wave a little.

From Science Daily ● Mar. 18, 2024

It is only by comparing different cases of refracted light at changing angles of incidence that the common factor, the constancy of the refractive index, is disclosed.

From Popular scientific lectures by Ernst Mach