at a slightly different angle, so the light disperses into its component colors.
Total Internal Reflection
When a beam of light strikes the boundary to a medium that has a lower index of
refraction, the beam bends away from the normal. As the angle of incidence
increases, the angle of refraction becomes larger. At some point, when the angle of
incidence reaches a critical angle, θc, the angle of refraction becomes 90°, which
means the refracted beam is directed along the surface.
For angles of incidence that are greater than θc, there is no angle of refraction; the
entire beam is reflected back into the original medium. This phenomenon is called
total internal reflection (sometimes abbreviated TIR).
Total internal reflection occurs when1) n 1 > n 2
and