RESUMEN
The linear characteristics of a vertically stacked multiring resonator (VMR) that can support a photonic bandgap with a defect located at the middle of the structure are investigated numerically. Initially, the spectral transfer characteristics of the uniform structure are studied. Then, the transmission properties of the VMR structure possessing a defect are investigated. The defect is realized by varying the waveguide width of one of the rings in the VMR chain. Finally, the existence of defect modes in the linear periodic array is numerically demonstrated by solving the corresponding coupled wave equations. Numerical results predict a high quality factor (Q) of up to 1.6x10(5) for this microcavity. We also show that our microcavity has a good insensitivity of quality factor to geometric imperfections.