Editing Optical ring resonators (section)

=== Interference ===
{{Main|Interference (wave propagation)}}
Interference is the process by which two waves superimpose to form a resultant wave of greater or less amplitude. Interference usually refers to the interaction of two distinct waves and it is a result of the linearity of Maxwell Equation. Interference could be constructive or destructive depending on the relative phase of the two waves. In constructive interference, the two waves have the same phase and, as a result, interfere in a way that the resulting wave amplitude will be equal to the sum of the two individual amplitudes. As the light in an optical ring resonator completes multiple circuits around the ring component, it will interfere with the other light still in the loop. As such, assuming there are no losses in the system such as those due to absorption, [[Evanescent wave|evanescence]], or imperfect coupling and the resonance condition is met, the intensity of the light emitted from a ring resonator will be equal to the intensity of the light fed into the system.