Pole-zero diagram approach to the design of coupled ring resonator arrays for photonic applications

Pole-zero diagrams are often employed in electronic filter design because of their simple and direct visualization of spectral characteristics. This paper proposes the use of pole-zero diagrams for tailoring the spectral response of ring resonator array filters for photonic applications. We show that there exist close relations between the pole-zero diagram features of the resonator array and its wavelength response characteristics, and demonstrate that the pole-zero diagram approach could be a very useful tool in the design of photonic devices based on resonator filters. In particular, we employ the pole-zero diagram approach for the case of a parallel-coupled ring resonator array for interleaving, and use this method to produce a new low crosstalk design