Simple structured broadband metamaterial absorbers with the same topology and structural ratio for selected wavebands

The design method of simple structured broadband perfect metamaterial absorbers (BPMAs) operating in selected wavebands from 150 nm to 16.5 μm over a wide range of incident angle is proposed. This type of BPMA composed of a metal substrate and a two-dimensional metal column hole array coated with a dielectric film is designed using finite-difference time-domain method. By selecting vanadium (V) to be the metallic material, a TiO₂/V BPMA for visible-near infrared waveband is analyzed theoretically and investigated experimentally. Moreover, theoretical results show that the absorption waveband of the TiO₂/V BPMA can be selected from 150 nm to 1.7 μm by adjusting the period, keeping the topology and structural ratio invariable. By selecting titanium (Ti) to be the metallic material, the absorption waveband of the TiO₂/Ti BPMA can be selected from 1.5 to 5.5 μm by adjusting the period, keeping the topology and structural ratio invariable. Finally, a Ge/Ti BPMA with high absorption spectra above 0.9 in waveband from 11.6 to 16.5 μm is provided to further prove this design method. The novel design idea might be helpful to simplify the work of design, and also to further exploit the design idea for broader spectral range from optical to radio waveband.