Monochromatic effect and polarization in near thermal field radiation of surfaces

The electromagnetic energy density, which was generated by fluctuational electromagnetic field, was investigated, as well as the radiative heat flux between two semi-infinite surfaces. The monochromatic effect to thermal radiation was analyzed. The result shows that the monochromatic effect dramatically influents the electromagnetic energy density and the radiative heat flux for silicon carbide (SiC). But this phenomenon does not exist for aluminum (Al). The polarization of the electromagnetic field was investigated. The result indicates that for SiC at micro/nanoscale, the electromagnetic energy density and the radiative heat flux are both dominated by p-polarization of the evanescent electromagnetic waves. The contributions of the s-polarization and that of the propagating waves can be neglected.