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The index of refraction of a material describes how fast light travels through a material and is defined by the speed of light in a vacuum (3 x 108 meters per second) divided by the speed of a given wavelength of light in the medium (Equation 2).
The most general form of Cauchy's equation is. where n is the refractive index, λ is the wavelength, A, B, C, etc., are coefficients that can be determined for a material by fitting the equation to measured refractive indices at known wavelengths.
9 cze 2005 · The refractive indices of the three main types of lens material are shown in Table 1. Polycarbonate has a refractive index (nd) of 1.59. 'Standard' plastic, or CR39, has a refractive index of 1.498, and plastics are available in further indices up to a maximum of 1.74 at the present time.
The most general form of this equation is = + + +, where n is the refractive index, λ is the wavelength, and A, B, C, etc., are coefficients that can be determined for a material by fitting the equation to measured refractive indices at known wavelengths.
The density varies, known as index of refraction, and the ABBE VALUES are different for the various materials. The ABBE VALUE is a number given to describe the amount of chromatic aberration of an ophthalmic lens material.
Refractive Index . The index of refraction or refractive index is an extremely important parameter in optics as it characterises the optical behaviour of materials. It is simply defined as the ratio of the speed of light in a vacuum c= 299792458 m/s, generally approximated to 3x10^8m/s, and the speed at which light propagates through
List of refractive indices. Many materials have a well-characterized refractive index, but these indices often depend strongly upon the frequency of light, causing optical dispersion. Standard refractive index measurements are taken at the "yellow doublet" sodium D line, with a wavelength (λ) of 589 nanometers.
