Transmission properties of a 3 x 3 cross-coupled double-ring resonator-based Photonic Integrated Circuit (PIC) filter

Abstract

We propose a novel Photonic Integrated Circuit (PIC)-based configuration for a double-ring resonator (DRR) that incorporates both (i) 3 x 3 coupler and (ii) cross-coupling directional coupler (DC) to increase its performance as a photonic filter. It is compared to a standard 3 x 3 DRR and its transmission properties were analyzed. We also investigated the effects of varying the two coupling parameters (k_r and k_x) on the transmission properties. The results show that the internal cross-coupling DC (k_x) significantly enhances the filter's capability through selection of appropriate coupling parameters.