Spectral Emissivity Prediction in Multi-Resonator Metamaterials Using Temporal Coupled-Mode Theory

The ability to design thermal emitters with a multi-resonant spectral response is essential for advancement of a wide variety of applications such as thermal management and sensing. To this end, several numerical methods for predicting the spectral response of complex, multi-resonator systems have been investigated. In this work, we propose an alternative semi-analytical approach to spectral prediction based on temporal coupled-mode theory. In our approach, a complex thermal emitter is fully described by a set of coupled-mode parameters, which can be straightforwardly calculated from simulations of single and double resonators. We demonstrate the accuracy of our method by predicting and optimizing spectral response in a coupled, multi-resonator system based on hBN ribbons. Our approach greatly reduces the computational overhead associated with spectral design tasks in coupled, multi-resonator systems. In addition, it provides valuable insights into the relationship between structural parameters and spectral response that is not always possible with purely numerical methods.