Polarization Manipulations of Mid-Infrared Thermal Emission Enabled by Plasmonic Metasurfaces

In this letter, we numerically demonstrate full Stokes parameters (FSP) control of mid-infrared (MIR) thermal emission by using plasmonic metasurface thermal emitter (PMTE) composed of Z-shaped meta-units. The spectral emissivities of 0°, 90°, 45°, 135° linear polarization (LP) and right/left-handed circular polarization (RCP/LCP) are adjusted by changing the shape of meta-units. As the result, the total degree of polarization (DoP), degree of linear polarization (DoLP), and degree of circular polarization (DoCP) in the normal direction could be adjusted in the ranges of 0-0.68, 0-0.67 and 0-0.26, respectively. The FSP engineering originates from the anisotropic symmetry of the meta-units and the relative phase delay between the resonant modes under LP light incidences. Finally, we briefly discuss potential applications of the PMTE as infrared polarization camouflage structure.