An add-drop filters using racetrack-shaped resonators coupled to straight waveguides across gaps which are larger compared with the conventional microcavity ring resonators is demonstrated. The finesse and maximum transmission of the device performance are characterized and show that they are related uniquely to the round-trip loss and the coupling factor, two fundamental characteristics of the resonator. Propagation loss in the cavity leads to an imbalanced Fabry-Perot even though the coupling factors are identical. To achieve unity transmittance, one would have to make the coupling factors slightly different to compensate for the loss.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Atomic and Molecular Physics, and Optics
- Electrical and Electronic Engineering