Total Internal reflection :
It is the phenomenon of light rays getting reflected back, when light rays from a denser medium are incident at the interface with a lighter medium at an angle greater than their critical angle.
Mirages in deserts or on hot roads at noon on summer days, transmission of telecommunication signals through fiber optic cables, decorative optical fiber vases.
Total internal reflection phenomenon is used in cameras also. Diamonds shine by this. In total internal reflection, energy of light rays is not lost. So in telecommunications the signals travel very far in optical fibers.