Mathematical modeling of Fabry-Perot resonators: II. Uniformly converging multimode equivalent-circuit models

Based on complex-variable analysis of a Fabry-Perot resonator as a multimode nonsymmetric two-port waveguide device, two versions of equivalent-circuit configurations are presented: Starting from a renewed study on single-mode two-pole circuits, we develop two respective multimode equivalent circuits of an almost identical configuration: one for the reflection coefficient and the other for the pass-through transmission coefficient. In the mathematics language of complex-variable analysis, the two models successfully "approximate" the two scattering coefficients through two "uniformly converging" partial-fraction series expansions.