An ultra-wideband polarization-insensitive optically transparent band-notched absorber

In this paper, a polarization-independent optical transparent absorber with a notch band has been designed, fabricated, and experimented. The proposed structure is composed of three layers made of indium tin oxide (ITO) films with different surface resistances separated by polydimethylsiloxane substrates, which can realize ultra-wideband absorption. The absorber presents two discrete absorption bands in the frequency range of 3.65-28.82 and 37.72-43.69 GHz, and reflective behavior from 31 to 36.57 GHz. Compared with existing notched band absorbers, this proposed structure has obvious advantages such as structure stability, polarization insensitivity, simple structure, and ultra-wide absorption bandwidth up to 155%. The prototype was fabricated and a reasonable agreement was obtained between the simulated and measured results.