# A report onRefractive index

Optical medium is a dimensionless number that gives the indication of the light bending ability of that medium.

- Refractive index

## Light

Electromagnetic radiation within the portion of the electromagnetic spectrum that is perceived by the human eye.

Electromagnetic radiation within the portion of the electromagnetic spectrum that is perceived by the human eye.

where θ1 is the angle between the ray and the surface normal in the first medium, θ2 is the angle between the ray and the surface normal in the second medium and n1 and n2 are the indices of refraction, n = 1 in a vacuum and n > 1 in a transparent substance.

## Optics

Branch of physics that studies the behaviour and properties of light, including its interactions with matter and the construction of instruments that use or detect it.

Branch of physics that studies the behaviour and properties of light, including its interactions with matter and the construction of instruments that use or detect it.

is the refractive index of the second material.

## Refraction

Redirection of a wave as it passes from one medium to another.

Redirection of a wave as it passes from one medium to another.

For light, refraction follows Snell's law, which states that, for a given pair of media, the ratio of the sines of the angle of incidence θ1 and angle of refraction θ2 is equal to the ratio of phase velocities (v1 / v2) in the two media, or equivalently, to the refractive indices (n2 / n1) of the two media.

## Dispersion (optics)

Phenomenon in which the phase velocity of a wave depends on its frequency; sometimes the term chromatic dispersion is used for specificity to optics in particular.

Phenomenon in which the phase velocity of a wave depends on its frequency; sometimes the term chromatic dispersion is used for specificity to optics in particular.

Most often, chromatic dispersion refers to bulk material dispersion, that is, the change in refractive index with optical frequency.

## Fresnel equations

Interface between different optical media.

Interface between different optical media.

When light strikes the interface between a medium with refractive index n1 and a second medium with refractive index n2, both reflection and refraction of the light may occur.

## Total internal reflection

Optical phenomenon in which waves arriving at the interface (boundary) from one medium to another (e.g., from water to air) are not refracted into the second ("external") medium, but completely reflected back into the first ("internal") medium.

Optical phenomenon in which waves arriving at the interface (boundary) from one medium to another (e.g., from water to air) are not refracted into the second ("external") medium, but completely reflected back into the first ("internal") medium.

It occurs when the second medium has a higher wave speed (i.e., lower refractive index) than the first, and the waves are incident at a sufficiently oblique angle on the interface.

## Wavelength

Spatial period of a periodic wave—the distance over which the wave's shape repeats.

Spatial period of a periodic wave—the distance over which the wave's shape repeats.

For electromagnetic waves the speed in a medium is governed by its refractive index according to

## Lens

Transmissive optical device which focuses or disperses a light beam by means of refraction.

Transmissive optical device which focuses or disperses a light beam by means of refraction.

Chromatic aberration is caused by the dispersion of the lens material—the variation of its refractive index, n, with the wavelength of light.