Broadband polarization-sensitive metamaterial absorber based on ladder network construction in the infrared region

Plasmonic resonant and metamaterial structures allow for manipulating the polarization properties of electromagnetic waves to achieve polarization beamsplitting. Broadband polarization-sensitive metamaterial absorber based on surface plasmon polaritonhas the advantages of high-energy utilization and excellent stability, which may replace traditional polarizing devices. Here, an absorber based on a ladder network construction is designed theoretically and investigated experimentally. The absorber can possess almost 92% average absorptivity for TM polarization light in 8 µm-12 µm range (experiment result: 83% from 7 µm-11 µm). It is especially sensitive to the polarization angle of incident light, and with the increase of polarization angle, the broadband absorption response can present analogously monotonous reduction. The theoretical and experiment results for TE polarization light are 12% and 25%, respectively. The broadband absorption response performs angle insensitive property under oblique incidence. The proposed metamaterial absorber open a path to realize broadband polarization-sensitive absorption based on simple nanostructure. It will possess great potential applications in high performance thermal detection and imaging fields.