  We explored a metal-insulator-metasurface structure exhibiting dual-band
absorption in the visible and infrared regions with almost perfect absorbance.
We demonstrated that the existence of the dual peak absorbance is due to the
excitation of propagating surface plasmon and localized surface plasmon mode.
We further utilized the excited degenerate propagating surface plasmon to
enhance the fluorescence emission of an emitter located on top of the
metasurface. This was accomplished by engineering a metasurface that excites a
degenerate mode with resonance absorption bands close to the emission
wavelength of fluorescent material. This condition helps to increase the rate
of excitation and emission of an emitter by generating additional electron
configurations when coupled to such metal-insulator-metasurface structures.
This approach offers relevant potential in radiative engineering techniques.
