total internal reflection

• total internal reflexion

total internal reflection (countable and uncountable, plural total internal reflections)

1. (optics, uncountable) A phenomenon where light, instead of passing into a medium of a lower refractive index and refracting away from the normal, is completely reflected by the boundary between the two media because it approaches at an angle greater than or equal to the critical angle.
2. (countable) An instance of this phenomenon.

• complete internal reflection

• Snell's law