Snell’s Law Refraction
Snell’s Law Refraction
Light bends when it crosses between media of different optical density; Snell’s law gives the new direction.
Snell’s law gives θ_2 = arcsin(n_1·sin θ_1/n_2). where n_1, n_2 are the refractive indices and θ_1 the incidence angle.
Inputs
n_1 := 1.0=1
n_2 := 1.33=1.33
theta_1 := 0.5236=0.52
Apply Snell’s law solved for the refraction angle.
theta_2 := asin(n_1·sin(theta_1)/n_2)=0.39 rad
Results
Light entering a denser medium bends toward the normal (smaller angle). The result is in radians; beyond a critical angle total internal reflection occurs instead.
Assumptions & limitations
- Ray optics.
- Smooth interface.
- Angles from the surface normal.