出典:Wiktionary
出典:Wikipedia
出典:『Wikipedia』 (2011/07/06 21:56 UTC 版)
The refractive index or index of refraction of a substance is a measure of the speed of light in that substance. It is expressed as a ratio of the speed of light in vacuum relative to that in the considered medium. The velocity at which light travels in vacuum is a physical constant, and the fastest speed at which energy or information can be transferred. However, light travels slower through any given material, or medium, that is not vacuum. (See: light in a medium).
屈折率.
the refractive index
refrangibility
clear homogeneous glass of known refractive index
a modulus
frequency-dependent conductance