Multiband terahertz absorbers using T-shaped slot-patterned graphene and its complementary structure

A dual-band absorber using monolayer periodically T-shaped slot-patterned graphene at terahertz frequencies is presented. By changing the dimensions or Fermi levels of the T-shaped slot-patterned graphene, both of the two absorption bands will be adjusted. The absorber has the characteristics of polarization independence and incident angle insensitivity. Also, its complementary structure, i.e., using periodically T-shaped strip-patterned graphene, is investigated to design another dual-band absorber. Moreover, two triband absorbers are studied through periodically loading four more T-shaped slots and complementary strips in square graphene lattices, respectively. This paper provides a significant paradigm for designing different graphene-based absorbers with multiple absorption bands. (C) 2020 Optical Society of America