Broadband terahertz absorber realized by self-assembled multilayer glass spheres

A broadband terahertz (THz) absorber consisting of multilayer glass spheres and polydimethylsiloxane (PDMS) was realized. The multilayer glass spheres were deposited by repeating a self-assembly method used to form monolayer glass spheres and by the spin-coating of PDMS to fill the gaps between the glass spheres. The average reflection at the surface of the absorber was 0.8% and the absorbance was higher than 98% in the frequency range between 0.7 to 2.0 THz.