Time-domain compact macromodeling of linear photonic circuits via complex vector fitting

In this paper, a novel baseband macromodeling framework for linear passive photonic circuits is proposed, which is able to build accurate and compact models while taking into account the nonidealities, such as higher order dispersion and wavelength-dependent losses of the circuits.Compared to a previous modeling method based on the vector fitting algorithm, the proposed modeling approach introduces a novel complex vector fitting technique.It can generate a half-size state-space model for the same applications, thereby achieving a major improvement in efficiency of the time-domain simulations.The proposed modeling framework requires only measured or simulated scattering parameters as input, which are widely used to represent linear and passive systems.Three photonic circuits are studied to demonstrate the accuracy and efficiency of the proposed technique.