index of refraction

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

index of refraction

noun

1. another name for refractive index

index of refraction

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.

Word History and Origins

Origin of index of refraction¹

First recorded in 1820–30

Example Sentences

"The DNA origami diamond lattice serves as scaffolding for titanium dioxide, which, on account of its high index of refraction, determines the photonic properties of the lattice. After coating, our photonic crystal does not allow UV light with a wavelength of about 300 nanometers to pass through, but rather reflects it," explains Posnjak.

From Science Daily

“The proper flow of waves on the ocean, waves interacting with characters, waves interacting with environments, the thin film of water that runs down the skin, the way hair behaves when it’s wet, the index of refraction of light underwater. We wanted to make it all physically accurate.”

From New York Times

The modern era of metamaterials can be traced back to 2000, when physicists David R. Smith of Duke University, the late Sheldon Schultz of the University of California, San Diego, and their colleagues created an engineered material unlike any seen before—a material with a negative index of refraction.

From Scientific American

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

From Scientific American

For all known natural materials, the index of refraction is positive, meaning that light always bends on the same side of the interface, with a larger or smaller angle from the interface as a function of the change in index.

From Scientific American