The modeling of MMI structures for signal processing applications - art. no. 68961G

Microring resonators are promising candidates for photonic signal processing applications. However, almost all resonators that have been reported so far use directional couplers or 2x2 multimode interference (MMI) couplers as the coupling element between the ring and the bus waveguides. In this paper, instead of using 2x2 couplers, novel structures for microring resonators based on 3x3 MMI couplers are proposed. The characteristics of the device are derived using the modal propagation method. The device parameters are optimized by using numerical methods. Optical switches and filters using Silicon on Insulator (SOI) then have been designed and analyzed. This device can become a new basic component for further applications. in optical signal processing. The paper concludes with some further examples of photonic signal processing circuits based on MMI couplers.