Definition

1. Noun:
   • A measure of how much light bends when passing from one medium into another: The refractive index is a dimensionless number that quantifies the reduction in the speed of light within a material compared to its speed in a vacuum. It determines the angle at which light is refracted (bent).

Usage

• The refractive index is a fundamental property in optics. It is used to calculate the path of light through lenses, prisms, and other optical materials. A higher refractive index indicates that light slows down more significantly in that medium.

Examples

• Noun:
  • Diamond has a very high refractive index, which contributes to its brilliant sparkle.
  • To design the lens correctly, the engineer must know the precise refractive index of the glass.
  • The refractive index of water is approximately 1.33.

Advanced Usage

• "Index of refraction": This is a synonymous term for refractive index.
  • The index of refraction for air is very close to 1.

Variants and Related Words

• Refraction (n): The bending of light as it passes from one transparent substance into another.
  • The refraction of light through a prism creates a spectrum of colors.
• Refract (v): To cause light to change direction as a result of entering a medium of different density.
  • The glass prism refracts the white light.

Synonyms

• Index of refraction: The direct synonym.
• Optical density: A related concept, though not a perfect synonym, as it often refers to a material's ability to slow light, which is directly related to its refractive index.

Related Phrases

• Snell's law: The formula that uses the refractive indices of two media to calculate the angle of refraction.
  • Snell's law is expressed as n₁ sinθ₁ = n₂ sinθ₂, where n is the refractive index.

Noun

1. the ratio of the velocity of light in a vacuum to that in a medium