Metasurface Design for Electromagnetic Wave Manipulation

Metasurfaces are ultrathin, two-dimensional arrangements of subwavelength scatterers engineered to mould the amplitude, phase and polarisation of electromagnetic waves. By judiciously designing the shape, orientation and composition of individual meta-atoms, one can tailor surface impedance and introduce abrupt phase discontinuities that direct, focus or reshape incident fields. Recent advances have extended static designs into active and reconfigurable regimes, incorporating lumped circuit elements or semiconductor diodes to achieve real-time control over beam steering, frequency response and polarisation conversion. The ability to synthesise arbitrary wavefronts in both reflection and transmission modes has unlocked applications across the microwave, terahertz and optical bands, with immediate relevance to wireless communications, imaging, sensing and compact optical systems. Underpinning these developments are principles drawn from Huygens’ equivalence, generalized sheet transition conditions and magnetoelectric coupling, which together furnish a versatile toolkit for next-generation wave-shaping devices.

Research from Nature Portfolio

Recent studies have introduced pulse-driven self-reconfigurable meta-antennas that exploit spatially arranged metasurfaces loaded with lumped circuits. By varying the time width of incident electromagnetic pulses, ordinary omnidirectional antennas can be switched to directional radiation patterns over broad temporal scales, offering novel degrees of freedom for selective reception, mutual communications and sensing within congested spectral environments. In an earlier foundational work, cavity-excited Huygens’ metasurface antennas demonstrated how co-located electric and magnetic surface currents can decouple excitation and radiation spectra, yielding near-unity aperture illumination efficiencies from low-profile apertures of arbitrary dimensions. This concept affords highly directive beams without edge-taper losses and has since been extended from microwave to terahertz and optical radiators. Further progress has been made in multifunctional dual-band metasurfaces capable of simultaneous anomalous reflection and transmission at distinct frequencies, enabling compact devices that independently tailor both reflected and transmitted wavefronts for terahertz applications.

Metasurface Design for Electromagnetic Wave Manipulation publication trend

The graph below shows the total number of articles in metasurface design for electromagnetic wave manipulation across all publications each year (not limited to Nature Index journals).

Technical terms

Metasurface: Two-dimensional artificial structure composed of subwavelength scatterers designed to control electromagnetic wavefronts.

Meta-atom: Fundamental unit cell of a metasurface whose geometry and composition determine the local amplitude, phase and polarisation response.

Huygens’ metasurface: Design principle exploiting co-located electric and magnetic surface currents to achieve arbitrary wavefront transformations with minimal reflection.

Phase gradient: Spatial variation of transmission or reflection phase across a metasurface, enabling beam steering, focusing or wavefront shaping.

Bianisotropy: Property of a metasurface whereby electric polarisation is induced by magnetic fields and magnetic polarisation by electric fields, permitting advanced field manipulations.

References

1. Pulse-driven self-reconfigurable meta-antennas. Nature Communications (2023).
2. Reconfigurable transmissive metasurface synergizing dynamic and geometric phase for versatile polarization and wavefront manipulations. Materials & Design (2023).
3. Cavity-excited Huygens’ metasurface antennas for near-unity aperture illumination efficiency from arbitrarily large apertures. Nature Communications (2016).
4. Bianisotropic metasurfaces: physics and applications. Nanophotonics (2018).
5. Simultaneous Realization of Anomalous Reflection and Transmission at Two Frequencies using Bi-functional Metasurfaces. Scientific Reports (2018).