▎ 摘　　要

An equivalent circuit model for a graphene-based high-efficiency tunable broadband THz polarizer is presented. The conditions for linear-to-circular polarization conversion in the transmission mode are utilized to derive a set of closed-form design formulas. Given a set of target specifications, the key structural parameters of the polarizer are directly calculated using this model. The proposed model is rigorously validated by comparing the circuit model and full-wave electromagnetic simulation results, from which it is found that the model is accurate and effective, accelerating the analysis and design processes. This offers a further step in developing a high-performance and controllable polarization converter with potential applications in imaging, sensing, and communications. (c) 2023 Optica Publishing Group