Synopsys offers a wide range of photonic simulation capabilities that cover device, circuit, and system level design. This article discusses modeling improvements made in late 2022 and early 2023 for circuit-level photonic simulations using the Synopsys OptSim product.
First, some background: photonic signals are quite complex in comparison to typical electrical signals used in IC design. Photonic signals can carry information in amplitude, phase, polarization, and spatial modes. Additionally, it is quite common to use multiple wavelengths of light to multiplex many signals onto a common waveguide. Lastly, for photonic IC (PIC) design, signal bidirectionality must also be understood as reflections within a PIC are quite common and can cause resonance and multipath interference. This complexity translates into modeling challenges for both the photonic and electrical domains.
Photonic devices in PICs are passive and active components. Passive elements are made from dielectric materials and are used to guide light. The propagation of light is influenced by the geometry and type of the dielectric material.
Active devices are made from semiconductors to facilitate energy transfers. In lasers, the applied electric field generates free photons, while in photodetectors, incident light generates free electrons. In modulators and active photonic filters, the applied electric field causes changes to the material’s refractive index, which also affects the optical signal’s phase and amplitude. This behavior can depend on wavelength, polarization, and temperature, and can be used to modulate light as well as to tune or select desired wavelengths.
Synopsys OptSim provides many tools for circuit-level photonic simulations; following are notable new features and modeling improvements.