EPHIC Models: General SPICE Photonic Models for Closed-Loop Electronic-Photonic Co-Simulation

This paper presents general SPICE photonic models for closed-loop electronic-photonic co-simulation. SPICE models are originally intended for electronic devices, which have significantly different physics compared to photonic devices. Most existing SPICE photonic models are specialized and fail to capture important features like multi-dimensional signals. It remains a key challenge to represent general photonic devices using SPICE models that include their essential features. To address the above challenge, we separate the signal meaning from its numerical result and adopt a numerically-equivalent approach to construct photonic models using native SPICE primitives. And the designer is left to interpret the meaning of the numerically-equivalent electronic signals, such as wavelength and polarization. Our models encompass the features of existing SPICE models, including wavelength dependence and bi-directional transmission, as well as new features beyond those. Specifically, polarization, optical Kerr effect, two-photon absorption, free carrier absorption, and free carrier dispersion are included in our SPICE models. Closed-loop polarization simulation is realized for the first time. We can quickly achieve frequency-domain simulation by DC sweep instead of stepped frequency transient simulations or frequency chirp-based methods. Our SPICE photonic models show excellent agreement with the simulation results of Verilog-A models and Lumerical models. Our SPICE photonic models are more efficient in co-simulation with SPICE electronic models than Verilog-A photonic models due to less compiling time and better compatibility. Our general models make the circuit design of electronics-photonics convergence (EPC) as convenient as that of traditional integrated circuits, paving the way for the circuit-level convergence of electronics and photonics.