Theory and application of temporal coupling mode for a SiC/CaF₂/Ag cell-based grating

Tailoring spectral thermal radiation properties via multiple resonances excited by micro/nanoscale-patterned structures plays a vital role in designing functional emitters and devices. However, predicting thermal radiation properties of a structure with multiple resonances-via a fast and accurate algorithm-is still challenging because of the complex mode coupling effects of different resonances. Herein, we establish a temporal coupling mode (TCM) model for a SiC/CaF₂/Ag cell-based grating by extracting the intrinsic parameters and coupling constants of the resonances. The accuracy and efficiency of the established TCM model for predicting absorption spectra of SiC/CaF₂/Ag gratings with multiple resonances in each unit cell is verified. Results indicate that the narrowband absorption of the SiC/CaF₂/Ag cell-based grating can be enhanced via the multiple-resonance coupling effects. This work provides an alternative tool for predicting absorption characteristics of complex structures with multiple-resonance coupling effects.