Abstract: An improved TCAD software tool includes a structure generator for generating a core single-pixel three-dimensional (3D) model including only front-end details of a single CIS pixel, a prototyping tool for generating modified CIS prototypes by automatically combining the core single-pixel 3D model with features and configurations included in selected modular templates, and a separate mesh generator for generating optical simulation models by generating optical meshes based on each CIS prototype's selected configuration. The modular templates include pre-configured optically-relevant (e.g., micro-lens and anti-reflection) structures, alternative (e.g., front-side illuminated or back-side illuminated, two-dimensional or 3D) pixel configurations, alternative array configurations, and alternative color filter patterns.