High-Q perfect absorption induced by the coupling of LSP and SPP modes

Abstract

At optical frequencies, we design an anisotropic metasurface to realize high-Q perfect absorption in numerical calculation. By establishing the Norton equivalent network model, we first reveal that the root cause of this phenomenon is the coupling excitation of the localized surface plasmon (LSP) mode and the surface plasmon polariton (SPP) mode. This absorber can realize bifunctional switching and is expected to realize the energy conversion of photons–SPP–photons. Meanwhile, we analyze the control of the structural design on high-Q perfect absorption. This research will provide theoretical guidance for the further development of applications related to high-Q perfect absorption such as absorption filters with specific wavelengths and narrow band photon emitters.