Fig. 4

Structures with the broken mirror and inversion symmetries, and thermal nonequilibrium system for circular polarized thermal emission control. a Fano resonance-based all-dielectric chiral metasurfaces are designed for thermal emitters with a high degree of circular polarization. b The optical Rashba effect induced circularly polarized thermal emission in an anisotropic SiC metasurface with a deformed kagome lattice, the panel on the right-hand side shows a spin-resolved projected dispersion diagram along the direction of φ = 60°. c Plasmon-based chiral nanostructures and the measured photothermal circular dichroism image with a single nanostructure resolution. d Spin-selective and directional emission control by a thermal metasurface. The metasurface is combined with a top layer (light gray) for the phase and polarization control and a bottom layer (dark gray) for the coherence control, respectively. e Chiral metasurface with F-shape meta-atoms for circularly polarized thermal emission. The emissivity spectrum and angle-resolved DoCP map show strong chiral effects. f Circularly polarized thermal emission generated from two coupled anisotropic antennas at different temperatures. Figures adapted from: a, ref [67]; b, ref [70]; c, ref [71]; d, ref [74]; e, ref [77]; f, ref [78]