PHYSICAL QUANTITY

Refractive index: formulas and units of measurement

Refractive index: symbol n, unit dimensionless. Formulas and explanations for Optics.

n

\text{dimensionless}

dimensionless quantity

KEY CONNECTIONS

Formulas

n = \frac{s i n α}{s i n γ}

n = sin α / sin γ

n = \frac{v _{1}}{v _{2}}

n = v₁ / v₂

n = \frac{λ _{1}}{λ _{2}}

n = λ₁ / λ₂

sin α_{0} = \frac{1}{n}

sin α₀ = 1 / n

n = \frac{n _{2}}{n _{1}}

n = n₂ / n₁

NOTATION

$n$: The refractive index is a characteristic of the retardation of light in a medium.
$\alpha$: Angle of incidence - the angle between the incident ray and the normal to the surface.
$\gamma$: The angle of refraction is the angle between the refracted ray and the normal to the surface.
$v_1$: The speed of light in the first medium is the speed of light propagation in the first medium.
$v_2$: The speed of light in the second medium is the speed of light propagation in the second medium.
$\lambda_1$: The wavelength in the first medium is the spatial period of light in the first medium.
$\lambda_2$: The wavelength in the second medium is the spatial period of light in the second medium.
$\alpha_0$: The limiting angle is the angle of incidence at which total internal reflection begins.
$n_2$: The refractive index of the second medium is the optical characteristic of the second medium.
$n_1$: The refractive index of the first medium is the optical characteristic of the first medium.

THEORY

PRACTICE