Refractive index

Refractive Index

The refractive index or index of refraction of a material is a dimensionless number that describes how light, or any other radiation, propagates through that medium. It is defined as the speed of light in vacuum divided by the speed of light in the material.

Explanation

The refractive index determines how much light is bent, or refracted, when entering a material. This is described by Snell's Law, which states that the ratio of the sine of the angles of incidence and refraction is equivalent to the ratio of phase velocities in the two media, or equivalently, to the indices of refraction of the two media.

Measurement

The refractive index can be measured using a variety of methods such as refractometry, interferometry, or total internal reflection.

Applications

Refractive index is used in a wide variety of applications. Lenses for eyeglasses, cameras, and other optical systems are designed using principles of refraction. It is also used in the field of optics to determine the optical properties of materials and in the field of telecommunications for the design of fiber optics.

See also

• Optical medium
• Snell's law
• Total internal reflection
• Optics
• Telecommunications

References

Refractive index Resources
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