Dual-band infrared perfect absorber based on asymmetric T-shaped plasmonic array

An infrared dual-band perfect absorber based on asymmetric T-shaped plasmonic array is designed and numerically investigated. Two distinct absorption peaks are achieved by localized surface plasmon polariton (LSPP) mode over a wide incident angular range. Both the absorption peaks can be finely tuned independently by varying the geometry of the structure. In our proposed structure, the period of the T-shaped structures becomes less and the multiple LSPP peaks are suppressed, which result in the sideband of absorption peaks very low. This dual-band perfect absorber has potential applications such as in infrared imaging devices, thermal bolometers, and wavelength selective radiators.