Internal Reflection
Total internal reflection (AKA as TIR), is the reflection of the total amount of incident light at the boundary between two medium. ... All the incident light is then reflected back into the medium from which it came, a phenomenon called total internal reflection. Total internal reflection will only occur when light travels from a higher-index medium toward a lower-index medium. ... For any angle of incident greater than the critical angle, light will undergo total internal reflection. ... In the experiment on the following page, we will be able to observe that the angles of reflection and refraction are not equal.