The spectral radiative effect of Si/SiO₂ substrate on monolayer aluminum porous microstructure

In this work, we have investigated theoretically the spectral radiative properties of a monolayer aluminum porous microstructure, including wavelength-selective transmission, reflection, and absorption. The finite-difference time-domain method for electromagnetics has been used to calculate the spectral radiative properties of the monolayer aluminum porous microstructure. It is found that the absorption spectra of the aluminum porous microstructure will generate two peaks within the wavelength ranging from 1.0 to 15.0 mm at normal incidence of light. Then the surface plasma polarition resonance could be observed clearly in the obtained results of this work, especially on the top surface near the orifice. Inside the porous structure, magnetic polariton is the crucial mechanism to elucidate for the power absorption enhancement. Furthermore, the absorption capacity of the aluminum porous structure with Si/SiO₂ substrate has been analyzed, to explain the influence of base on the monolayer porous material. The findings indicate that the absorptance peak at 3 mm incident wavelength significantly improved with silicon substrate, while that of silica substrate has little difference with aluminum porous plate. The silicon and silica bases disrupted the distribution of the electromagnetic fields of the original aluminum porous structure, and form a new magnetic field within the subbases. Meanwhile the internal microcavity polarition of the porous structure has enhanced obviously near the bases.