Cascaded and parallel IIR microwave photonic filters based on homogeneous multicore fibers

We propose and demonstrate two types of infinite impulse response (IIR) microwave photonic filters (MPFs) with different structures, named cascaded structure and parallel structure. Both structures are based on the homogeneous multicore fiber (MCF) in which the inter-core power coupling has been established by tapering technique. The quality factors (Q factors) of cascaded and parallel structures are 143 and 136 respectively, which is much higher than that of one single IIR filter. These two structures show good reconfigurability and tunability by adjusting optical power and time delay. We anticipate that microwave photonics systems will benefit from these two types of IIR-MPFs in terms of compactness, reconfigurability, tunability and performance stability.