Analysis of Thermal Crosstalk in Photonic Integrated Circuit Using Dynamic Compact Models

Thermal modeling of photonic integrated circuits (PICs) is required for circuit design and the development of thermal control algorithms. In this work, we present a methodology for obtaining a compact dynamic thermal RC model of a PIC. PICs are sensitive to thermal coupling, and in this article, it is shown that traditional resistive coupling does not suffice, and a new coupling method is derived. The case study to which the new methodology is applied is a dense wavelength-division multiplexing ring filter with eight channels. With the obtained RC model, the computational time is reduced from 5.5 h for finite element simulation to < 1 s for a single-step response. Using the compact model, circuit-level analysis of frequency response is carried out. Because of its high computational efficiency, the compact model opens possibilities for simulating thermal tuning algorithms.