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refractive index

refractive index

1 6.1
A number that shows how much a material slows light compared with empty space
  • noun
  • /rɪˈfræktɪv ˈɪndɛks/
  • Specialized
translation icon : índice de refracción
  • In glasses, the losses within this optic window are dominated by scattering from static fluctuations of the refractive index and by absorption by impurities and structural defects.
  • refractive index of glass
  • refractive index of a medium
  • refractive index changes

And that's because of its high refractive index and its size.

Examples

  • Like many things in physics, refractive index isn't as simple as we learned in high school.

    Academic text (2001)
  • The linear optical properties of a material are determined by its refractive index.

    Academic text (2012)
  • So N here is the refractive index of this cell.

  • And that's because of its high refractive index and its size.

  • Often, we can describe media by their refractive indices.

    Academic text (1999)
  • Anything transparent becomes practically invisible if put into any media of the same refractive index.

  • So, for example, glass has a refractive index that varies with wavelength.

  • Even when passing through natural materials with the highest refractive indexes, light can only bend so far.

  • "SPR uses light reflected off thin metal films," Medina explains. "Toxin molecules in the sample bind to the sensor surface, and the refractive index at the surface changes."

    Academic text (2005)
  • The refractive index of water is approximately 1.33, indicating how much it slows down light.

Synonyms

index of refraction
vsrefractive index
  • Specialized
1 6.9

A number showing how much light slows in a material compared to empty space

is the same numeric measure indicating how much a medium slows light
refractivity
vsrefractive index
  • Specialized
9.3

The amount a material bends light and other waves

is the specific numeric ratio not the general degree of bending
refractiveness
vsrefractive index
  • Specialized
9.8

The amount a material bends light when the light passes through it, like water or glass

is the measured numeric ratio not the general material quality

Surface Forms

Morphology

refractive + index

The phrase is compositionally built: 'refractive' relates to bending/slowing of light and 'index' denotes a numeric indicator, so a learner who knows both words can infer it is a number that quantifies refraction. This construction is also cross-linguistically common (e.g. Spanish índice de refracción, French indice de réfraction), supporting its predictability for learners.

Etymology

Refractive index comes from the idea of 'refraction', which is light bending when it goes into something like water. For example, a straw looks bent in a glass. The word refractive points to that bending and index means a number that compares how fast light moves in empty space and in the material, so the term tells how much the material slows and bends light.