Nonperturbative Zou-Wang-Mandel effect

Nonperturbative expressions for the Zou-Wang-Mandel interference patterns and normalized first-order coherence function are derived by bringing the canonical formalism of continuous-variable (CV) Gaussian states to bear on the mode-structure of the experiment. Generalizations to two-mode squeezing networks or $\mathcal{H}$-graph states with more than four modes directly follow from the general method used to analyze the minimal example.