Three-dimensional propagation analysis of coupling efficiency using segmentation and local normal mode expansion for vertically coupled microring resonator filter

A novel three-dimensional (3-D) propagation analysis of coupled waveguides using local normal modes and the segmentation along the propagation axis was developed. The coupling efficiency of vertically coupled microring resonators was optimally designed using this analysis. The computation time is much faster and the required memory capacity is much smaller than those of the 3-D finite-difference time-domain (FDTD) method.