Accurate Transmission and Crosstalk Estimation Methodology for Silicon Photonic WDM Filters

As one of the key components in wavelength-division multiplexing (WDM) circuits, integrated WDM filters that are implemented on the silicon-on-insulator (SOI) platform provide a low-cost and compact solution for combining and separating multiple optical carrier signals. WDM filters are usually represented by their transmission characteristics in the frequency domain whereas their time-domain evaluation is of paramount importance for co-designing and co-optimizing with other electronic and photonic devices for achieving high-speed and high-capacity WDM circuits. This article proposes an accurate and efficient time-domain modeling and simulation approach for WDM filters. The method starts with transmission parameters and allows for the comprehensive representation of all time-domain transmission and crosstalk characteristics within a single unified model. Notably, the built model could take into account dispersion and wavelength-dependent effects, which are often overlooked by some other modeling techniques. Through a single simulation of such model, transmission and crosstalk signals at all channels can be obtained simultaneously. To illustrate the advantages of our proposed approach, we have conducted a study involving three different types of WDM filters.