Evanescent wave coupling

Evanescent wave coupling is like two people playing catch with a beach ball in a pool. The beach ball is the evanescent wave, and the two people are two objects or components that are close together. When one person throws the beach ball to the other, it is like sending a wave of energy from one to the other. When the wave touches the other person, it gives some of the energy to that person, just like the beach ball bounces off the second person's hand and transfers some of its energy to them. This transfer of energy is called evanescent wave coupling.