Optics
Snell's Law
Describes how light bends when passing between media with different refractive indices.
Variables
n_1unitless
Refractive index of medium 1
\theta_1°
Angle in medium 1
n_2unitless
Refractive index of medium 2
\theta_2°
Angle in medium 2
Derivation
Derived from Fermat's principle of least time or from the wave nature of light at boundaries.
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Common questions
What is the Snell's Law formula?
Snell's Law is written n₁ sinθ₁ = n₂ sinθ₂. Describes how light bends when passing between media with different refractive indices. It belongs to Optics, under Refraction.
What are the units in n₁ sinθ₁ = n₂ sinθ₂?
In SI units, n_1 is refractive index of medium 1 (dimensionless); \theta_1 is angle in medium 1, measured in °; n_2 is refractive index of medium 2 (dimensionless); \theta_2 is angle in medium 2, measured in °.
How is the Snell's Law formula derived?
Derived from Fermat's principle of least time or from the wave nature of light at boundaries. The result is n₁ sinθ₁ = n₂ sinθ₂.