Investigation of coupling conditions for Fiber Bragg Grating Ring Resonators

This paper deals with an investigation of the coupling conditions in order to achieve optimal operation of Fiber Bragg Grating Ring Resonators (FBGRRs). In particular, in analogy with conventional ring resonators, these devices show a critical coupling condition, fulfilled when the power coupled from the bus waveguides to the ring compensates the loss within the ring resonator over a round trip. By adopting this physical condition, improved Q factors can be achieved.