Integrated Multi-Functional Optical Filter Based on a Self-Coupled Microring Resonator Assisted MZI Structure

In general, to fit various application scenarios, different types of optical filters are needed and designed individually, which leads to high cost and long development times. Here we proposed a reconfigurable multi-functional optical filter based on self-coupled microring assisted MZI structure, which can be reconfigured into five different kinds of devices, including the optical switch, asymmetric MZI filter, ring assisted MZI filter, double injection microring resonator and self-coupled micro-ring assisted MZI filter. An analytical model was established based on the transfer matrix method to investigate the function reconfigurations, which were then verified experimentally by simply controlling the six thermo-optical phase shifters in the structure. Furthermore, our proposed reconfigurable multi-functional optical filter provides performances that are comparable to the individual devices or even better, which has the potential to be applied in the integrated optical signal processing and microwave photonics systems.