Broadband Metamaterial Absorption Technologies

Broadband metamaterial absorbers are engineered assemblies of subwavelength resonators that achieve near-perfect absorption across a wide spectrum by tailoring geometry, materials and resonant interactions. By combining overlapping resonances—such as localised and propagating surface plasmon modes, magnetic polaritons and cavity effects—these structures trap incident radiation and dissipate it as heat or channel it into functional layers. Advances in lossy metals, semiconductor integration and multilayer metasurfaces have driven ultrathin designs that remain effective over extreme bandwidths, while retaining angular and polarisation insensitivity. Such absorbers find global applications in thermal emission control, energy harvesting and photovoltaics, infrared imaging and sensing, radiative cooling, camouflage and stealth technologies, as well as in emerging photonic and optoelectronic devices.

Research from Nature Portfolio

Recent studies have advanced two foundational approaches. One employs titanium-based nanodisk arrays on dielectric-coated metallic substrates to reduce the quality factor of localised resonances and combine them with propagating surface plasmon modes, yielding over 90 per cent absorption from near-infrared wavelengths of around 900 nm up to 1.8 µm in an ultrathin, polarisation-insensitive film. Another strategy tailors the geometric skin depth of metallic layers in metal–insulator–metal configurations to exchange intrinsic Ohmic losses for useful optical absorption within semiconductor layers, transforming conventional plasmonic absorbers into photovoltaic-active devices that harvest 75–95 per cent of incident light in the active medium.

Broadband Metamaterial Absorption Technologies publication trend

The graph below shows the total number of articles in broadband metamaterial absorption technologies across all publications each year (not limited to Nature Index journals).

Technical terms

Metamaterial absorber: Engineered composite of subwavelength resonators that traps and dissipates electromagnetic energy with near-unity absorption over a designated spectral range.

Localised surface plasmon resonance (LSPR): Confinement of collective electron oscillations within metallic nanostructures, producing intense local fields and narrowband absorption peaks.

Propagating surface plasmon resonance (PSPR): Surface-bound electromagnetic waves at a metal–dielectric interface that channel incident light along the interface, extending absorption bandwidth.

Metasurface: Planar array of subwavelength resonators engineered to manipulate electromagnetic waves via spatially varying amplitude, phase or polarisation.

Quality factor (Q factor): Dimensionless metric of resonance sharpness, defined as the ratio of the resonant frequency to its full-width at half-maximum bandwidth.

References

1. Broadband near-infrared metamaterial absorbers utilizing highly lossy metals. Scientific Reports (2016).
2. Exchanging Ohmic Losses in Metamaterial Absorbers with Useful Optical Absorption for Photovoltaics. Scientific Reports (2014).
3. Ultra-broadband metamaterial absorbers from long to very long infrared regime. Light: Science & Applications (2021).
4. Design of an ultra-broadband near-perfect bilayer grating metamaterial absorber based on genetic algorithm.. Optics Express (2020).