While system-level simulation can allow designers to assess optical system performance via measures such as signal
waveforms, spectra, eye diagrams, and BER calculations, component-level modeling can provide a more accurate
description of coupling into and out of individual devices, as well as their detailed signal propagation characteristics. In
particular, the system-level simulation of interface components used in optical systems, including splitters, combiners,
grating couplers, waveguides, spot-size converters, and lens assemblies, can benefit from more detailed component-level
modeling. Depending upon the nature of the device and the scale of the problem, simulation of optical transmission
through these components can be carried out using either electromagnetic device-level simulation, such as the beampropagation
method, or ray-based approaches. In either case, system-level simulation can interface to such componentlevel
modeling via a suitable exchange of optical signal data. This paper presents the use of a mixed-level simulation
flow in which both electromagnetic device-level and ray-based tools are integrated with a system-level simulation
environment in order to model the use of various interface components in optical systems for a range of purposes,
including, for example, coupling to and from optical transmission media such as single- and multimode optical fiber.
This approach enables case studies on the impact of physical and geometric component variations on system
performance, and the sensitivity of system behavior to misalignment between components.