Tunable narrow terahertz absorption of one-dimensional photonic crystals embedded with Dirac semimetal-dielectric defect layers.

The absorption characteristics of one-dimensional photonic crystals embedded with Dirac semimetal-dielectric defect layers are studied using the transfer matrix method. Numerical results show that our proposed structure can realize near-perfect narrow absorption for its strong field localization effects. The absorption frequency is tunable by adjusting the Fermi energy of the Dirac semimetal, temperature, permittivity of the dielectric, and the structural parameters. Moreover, double or multiple absorption channels can be achieved by changing the structure. Furthermore, the absorption performance is wide-angle and insensitive to polarization of the incident wave. Such properties exhibit potential value in designing selective absorbers and thermal detectors.