This is a numerical investigation of a recently proposed formulation, called coupled transverse-mode integral equation (CTMIE), for analyzing EM field properties in general 2-D dielectric waveguide devices. The device is first approximated by stack of piece-wise 1-D horizontally layered structures. Transverse field components on the interface between waveguide slices are unknown functions, which are governed by a coupled integral equation. When unknowns are expanded as a linear combination of given functions, CTMIE is converted to a coupled block matrix equation. We study three waveguide devices, in detail, to understand the relation between modeling parameters and accuracy and convergent rate of the solutions. Examples include a step waveguide junction, a multi-mode interferometer power cross coupler and a linearly tapered waveguide. All results are verified with independent calculations using other proven methods.
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