A study on high-order optical filters based on coupled resonators through the slot waveguide in two-dimensional photonic crystal

Abstract

In this paper, we present the theoretical and numerical results of the high-order optical filters based on the slotted two-dimensional photonic crystal waveguide conjugated with multiple coupled resonators. Slotted waveguide is designed to enhance the electromagnetic intensity and confine the light in the narrow area with low refractive index, so that the figure-of-merit (Q/V) of the resonators is significantly enhanced. The coupling among the resonators is analyzed theoretically, based on the coupled-mode theory in time (CMT). We perform the finite-difference time-domain (FDTD) simulation to confirm the CMT analysis. It is shown that the good agreement between the theory and the simulation. This result will provide a general guide line for planar photonic integrated circuits.