Pseudo-anapole regime in terahertz metasurfaces

Abstract

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Optically transparent and flexible-assembled metasurface rasorber for infrared-microwave camouflage based on a hybrid anapole state

“…First, it acts as an IR-reflecting mirror that can reflect long-wavelength IR waves, thus suppressing thermal radiation. Second, it also works as a low-pass filter allowing microwave communication signals (10)(11)(12)(13)(14)(15)(16)(17) to transmit efficiently. Third, it helps the metasurface support enhanced electromagnetic multipole moments to sustain hybrid anapole states, which support the desired absorption-transmission-absorption in the microwave band.…”

“…In particular, the destructive interference of their radiating electromagnetic fields produces significantly suppressed far-field radiation states, giving rise to the so-called anapole state. [9][10][11][12][13] For example, the destructive interference between an electric dipole, and an electric toroidal dipole results in the well-known electric dipole anapole state, in which electric dipole radiation is significantly suppressed, and thus is very beneficial for the absorption of electromagnetic waves [14][15][16][17][18] and the enhancement of nonlinear effects. [19][20][21] However, it is still accompanied by the non-negligible radiation contribution of electric quadrupole, magnetic dipole, and magnetic quadrupole, thus facing a fundamental limitation in achieving nonradiating behaviour.…”

Antisymmetric toroidal plasmonic metasurfaces

“…So far, the major existing toroidal metamaterials are designed to achieve pronounced toroidal dipole by modifying toroidal metamolecules. When two toroidal dipoles are oriented either antiparallel or parallel in a longitudinal or transverse arrangement, the coupling between two toroidal dipoles can tailor the optical responses and form exotic optical states [10][11][12]. However, researchers pay more attention to the signal toroidal dipole and ignore the interaction between two toroidal dipoles.…”