Reconfigurable microwave photonic filter based on parallel-cascaded microrings assisted with a Mach–Zehnder interferometer

A reconfigurable microwave photonic filter based on parallel-cascaded silicon microrings is proposed and demonstrated with numerical simulation. A Mach–Zehnder interferometer (MZI) is introduced between two adjacent microrings. Through tuning the MZI, the feedback ratios of adjacent rings can be tuned so that both the bandwidth and shape of filter response can be adjusted while the central wavelength remains constant and the sidelobes can also be remarkably suppressed. (paper)