Temporal coupled mode theory for all-dielectric perfect absorbers

Mechanism of the two-port one input mirror-symmetric all-dielectric disk array perfect absorbers is studied by temporal coupled mode theory. The perfect absorption is resulted from the degenerate critical coupling of EH111 and HE111 modes of the dielectric disks. Analytical absorption with parameters extracted from Eigen-frequency analysis matches well with that by Scattering parameter simulations, we also show that the asymmetric total field is due to the different symmetry of the two modes. The effect of the geometric parameters and material loss tangent is also investigated, which can guide the design of such all-dielectric perfect absorbers.