Universal relations for coupling of optical power between microresonators and dielectric waveguides

The most basic and generic configuration, which consists of a unidirectional coupling between a ring resonator and a waveguide, is considered. The fundamental working equations required to describe the associated power transfer are derived and the application of this geometry to a variety of optical phenomena is discussed. These phenomena include ‘adddropping’ of optical beams, adddrop filtering and optical power switching.