One variety of it involves an evanescent wave extending across a separating
One variety of it involves an evanescent wave extending across a separating medium and the flow of energy through that medium. It only occurs when the incident light is in the medium with the higher index of refraction, and it can be used to losslessly redirect a beam in the direction of its source using a specifically shaped prism. The guiding principle behind fiber optics, FTP, name this phenomenon in which the incident angle is so high that refraction does not occur.
One variety of it involves an evanescent wave extending across a separating medium and the flow of energy through that medium.
{Total Internal Reflection}