All-dielectric water-based metamaterial absorber in terahertz domain

An all-dielectric metamaterial absorber consisting of water arrays encapsulated in polytetrafluoroethylene (PTFE) container is proposed. The absorber can afford the absorptivity exceeding 90% over the broadband frequency band ranging from 0.3 THz to 1.5 THz and the relative absorption bandwidth is up to 133%. The distributions of electric field and magnetic field as well as power loss density are analyzed and reveal that magnetic resonance at the top border between water and PTFE plays a more important role than electric resonance and most of the incident power is dissipated here. Furthermore, the absorber has excellent thermal stability as well as insensitivity of polarization and incident-angle. Endowed with these excellent performance as well as the advantage of low cost and eco-friendly materials, the proposed absorber can be expected to find extensive applications in terahertz domain. • An all-dielectric metamaterial absorber based on water resonator encapsulated in PTFE shell is proposed for terahertz domain. • The absorptivity exceeds 90% over the frequency range of 0.3 - 1.5 THz and the relative absorption bandwidth is up to 133%. • Magnetic resonance at the top border between water and PTFE plays a more important role than electric resonance. • The absorber exhibits excellent thermal stability as well as insensitivity of polarization and incident-angle.