Tunable Microwave Photonic Filter Based on Silicon Nitride MZI-Assist Micro-Ring Resonator

We study a tunable microwave photonic filter by a MZI-assist MRR structure with a high thermo-optic tuning efficiency utilizing SiNx material platform, showing a wide central frequency tuning range over a FSR of 50 GHz, with a tuning efficiency of 0.0115 nm/mW, thanks to the cantilever adiabatic waveguide structure. A maximum extinction ratio of 22 dB at 1553.46 nm wavelength with the high quality factor of 1.2 × 10
⁵
can be achieved by tuning the coupling rate between the bus waveguide and the ring resonator.