Fig. 1. Multi-slot butterfly dipole

Fig. 2. Schematics of unit structure. (a) Y-Z view; (b) X-Y view

Fig. 3. Electric field Ex distributions in plane at z=0 nm. (a) λ=880 nm, multi-slot butterfly dipole; (b) λ=1200 nm, multi-slot butterfly dipole; (c) λ=880 nm, butterfly dipole; (d) λ=1200 nm, butterfly dipole; (e) absorption characteristics of multi-slot butterfly dipole and butterfly dipole

Fig. 4. Electric field Ex distributions in plane at z=0 nm for λ=1000 nm. (a) Seamless; (b) slot number n=2; (c) slot number n=4; (d) slot number n=6; (e) slot number n=8; (f) slot number n=10

Fig. 5. Electric field Ex distributions in plane at z=0 nm for λ=1450 nm. (a) Without nanowires; (b) with nanowires; (c) absorption characteristics of two classes of structures

Fig. 6. Absorption characteristics of different materials. (a) Absorptivity; (b) average absorptivity

Fig. 7. Multi-slot butterfly dipole nano-antenna

Fig. 8. (a) Absorption spectrum and (b) reflectance spectrum of multi-slot butterfly dipole nano-antenna; electric field Ex distributions of multi-slot butterfly dipole nano-antenna array in plane at z=0 nm plane for (c) λ=680 nm, (d) 880 nm, (e) 1080 nm, (f) 1200 nm, (g) 1450 nm and (h) 1680 nm

Fig. 9. Schematic of nano-antenna central gap distance and absorption characteristics under different distances. (a) Schematic; (b) absorptivity; (c) average absorptivity

Fig. 10. Electric field Ex distributions in plane at z=0 nm for λ=800 nm. (a) D=80 nm; (b) D=100 nm; (c) D=120 nm; (d) D=140 nm

Fig. 11. Absorption characteristics under different slot numbers n. (a) Absorptivity; (b) average absorptivity

Fig. 12. Absorption characteristics under different film thicknesses h. (a) Absorptivity; (b) average absorptivity

Fig. 13. Influences of (a) polarization angle and (b) inclined incidence angle on absorption characteristics