A two-dimensional multiphysics simulation method for optical-thermal-electrical coupling in microbolometers for LWIR applications

This paper presents a two-dimensional multiphysics simulation method for modeling the optical-thermal-electrical coupling behavior of microbolometers operating in the long-wave infrared (LWIR) band, implemented using COMSOL Multiphysics. By comparing the simulation results of both 2D and 3D models, the accuracy and validity of the 2D approach are verified. The proposed method significantly reduces modeling complexity and computational cost, making it highly suitable for iterative device optimization. Unlike traditional single-domain simulations—such as optical-thermal or thermal-electrical coupling — the proposed fully integrated multiphysics framework accounts for interactions among all relevant physical domains simultaneously. This enables a more intuitive understanding of the device's response characteristics and provides valuable guidance for the design of the back-end readout circuitry.