index of refraction
noun Optics.
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). Symbol: n
Also called
index,
refractive index.
Origin of index of refraction
First recorded in 1820–30
Words nearby index of refraction
index futures,
index librorum prohibitorum,
index mineral,
index number,
index of industrial production,
index of refraction,
index plate,
index set,
index-link,
index-linked,
indexation
Example sentences from the Web for index of refraction
He'd gotten an index-of-refraction reading on crystals too small to be seen except through a microscope.
The Hate Disease |William Fitzgerald Jenkins
British Dictionary definitions for index of refraction
Scientific definitions for index of refraction
index of refraction
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.