释义 |
index of refraction
index of refractionn. The ratio of the speed of light in a vacuum to the speed of light in a medium under consideration. Also called refractive index.index of refraction n (General Physics) another name for refractive index in′dex of refrac′tion n. a number indicating the speed of light in a given medium, usu. as the ratio of the speed of light in a vacuum or in air to that in the given medium. [1820–30] in·dex of refraction (ĭn′dĕks′) The ratio of the speed of light in a vacuum to the speed of light in another medium, such as water or oil.ThesaurusNoun | 1. | index of refraction - the ratio of the velocity of light in a vacuum to that in a mediumrefractive indexratio - the relative magnitudes of two quantities (usually expressed as a quotient) | Translationsindex of refraction
index of refraction[′in‚deks əv ri′frak·shən] (optics) The ratio of the phase velocity of light in a vacuum to that in a specified medium. Also known as absolute index of refraction; absolute refractive constant; refractive constant; refractive index. index of refraction
index of refraction1. The ratio of the angle made by the incident ray with the perpendicular (angle of incidence) to that made by the emergent ray (angle of refraction). 2. The ratio of the speed of light in a vacuum to its speed in another medium. The refractive index of water is 1.33; that of the crystalline lens of the eye is 1.413. Synonym: refractive indexSee also: indexindex of refraction A measure of the optical density of a transparent material such as glass or the cornea. It is the ratio of the speed of light through the material to its speed in a vacuum.Index of refractionA constant number for any material for any given color of light that is an indicator of the degree of the bending of the light caused by that material.Mentioned in: Eye Glasses and Contact Lensesindex of refractionThe ratio of the speed of light in a vacuum or in air, c, to the speed of light in a given medium, v. Symbol: n. Hence,n = c/vThe speed of light in a given medium depends upon its wavelength. Consequently, the index of refraction varies accordingly, being greater for short wavelengths (blue) than for longer wavelengths (red). The index of refraction forms the basis of Snell's law, which quantitatively determines the deviation of light rays traversing a surface separating two media of different refractive indices. Syn. refractive index. Plural: indices. See dispersion; law of refraction; gradient-index lens; high index lens; speed of light; refractometer.
Table I3 Refractive indices of some transparent media at selected wavelengths | spectral line | | G | | F | | D | | C | | A | Origin | | Calcium | | Hydrogen | | Sodium | | Hydrogen | | Oxygen | wavelength (nm) | | 430.8 | | 486.1 | | 589.3 | | 656.3 | | 759.4 | aqueous or vitreous humour | | 1.3440 | | 1.3404 | | 1.3360 | | 1.3341 | | 1.3317 | crystalline lens | | 1.4307 | | 1.4259 | | 1.4200 | | 1.4175 | | 1.4144 | spectacle crown | | 1.5348 | | 1.5293 | | 1.5230 | | 1.5204 | | 1.5163 | dense flint | | 1.6397 | | 1.6290 | | 1.6170 | | 1.6122 | | 1.6062 |
Table I4 Index of refraction n of various media for sodium light (λ = 589.3) | air | 1.00 | water (at 20ºC) | 1.333 | spectacle crown glass | 1.523 | flint glass (dense) | 1.62 | flint glass (extra dense) | 1.65-1.70 | titanium oxide glass | 1.701 | calcite crystal | | ordinary ray | 1.658 | extraordinary ray | 1.486 | quartz crystal | | ordinary ray | 1.544 | extraordinary ray | 1.553 | | | diamond | 2.42 | Canada balsam | 1.53-1.54 | CR-39 | 1.498 | polycarbonate | 1.586 | silicone rubber | 1.44 | CAB | 1.47 | PMMA | 1.49 | HEMA | 1.43 | hydrogel polymer | | 20% water content | 1.46-1.48 | 75% water content | 1.37-1.38 | eye | | tears | 1.336 | cornea | 1.376 | aqueous humour | 1.336 | crystalline lens (average effect) | 1.42 | vitreous humour | 1.336 | LegalSeeIndexFinancialSeeindexAcronymsSeeinclusive orindex of refraction
Synonyms for index of refractionnoun the ratio of the velocity of light in a vacuum to that in a mediumSynonymsRelated Words |