Advanced macromodeling technique for passive photonic integrated circuits: a baseband Loewner matrix approach

For accurate circuit-level simulations, passive photonic integrated circuits (PICs) must be modeled in the time domain, using their frequency responses. The complex vector fitting (CVF) method has been established as a reliable technique for constructing time-domain state-space models of passive PICs. This paper introduces a more advanced method, called the baseband Loewner matrix approach, which offers enhanced efficiency compared to CVF. The resulting models are significantly more compact while maintaining accuracy. The advantages of the proposed method are demonstrated through three passive PIC case studies.