Coherent Perfect Absorption in Optical Metasurfaces

Coherent perfect absorption (CPA) in optical metasurfaces harnesses the interplay between engineered subwavelength resonators and controlled interference to achieve complete dissipation of incoming light. By tailoring the amplitude, phase and polarisation of counter-propagating beams, planar metamaterial layers can be driven to their scattering zeros, converting incident energy into heat or other forms of internal excitation with near-unit efficiency. This phenomenon rests on the non-Hermitian nature of resonant systems, where precise balancing of radiative loss and material absorption yields total energy trapping. Advances in metasurface design—spanning plasmonic nanoantennas, dielectric resonators and hybrid graphene structures—have expanded the accessible spectral range from visible to mid-infrared, while integration with optical fibres and on-chip waveguides has opened routes to compact, high-speed photonic components. Applications extend from ultrafast all-optical logic and single-photon detection to energy harvesting, radar cloaking and quantum information processing.

Research from Nature Portfolio

Dynamic switching between coherent perfect absorption and parametric amplification has been demonstrated in a nonlinear spoof-plasmonic waveguide. By introducing a judicious nonlinearity, the device relaxes stringent requirements on gain–loss balance and reframes CPA and amplification as two sides of the same resonant response, enabling continuous tuning of signal gain from strong absorption to high amplification over sub-millimetre propagation lengths. In a separate development, the integration of plasmonic metamaterial films on optical fibre tips has realised all-optical logic gates (XOR, NOT, AND) operating at tens of gigabits per second with sub-milliwatt power levels, illustrating coherent control of light with light in a practical, fully packaged format. Extending to the quantum regime, deeply subwavelength absorbers have been shown to capture single photons deterministically via standing-wave excitation, achieving near-unity coupling into plasmonic modes and paving the way for ultrasensitive detection and on-chip quantum photonic operations.

Coherent Perfect Absorption in Optical Metasurfaces publication trend

The graph below shows the total number of articles in coherent perfect absorption in optical metasurfaces across all publications each year (not limited to Nature Index journals).

Technical terms

Coherent Perfect Absorption (CPA): Complete dissipation of incident electromagnetic energy via controlled interference and material loss.

Metasurface: A two-dimensional array of subwavelength resonators engineered to manipulate amplitude, phase or polarisation of light.

Plasmonic Resonance: Collective oscillation of conduction electrons in a metallic nanostructure, leading to strong local field enhancement.

Standing Wave: A stationary interference pattern formed by two counter-propagating coherent waves.

Scattering Zero: A complex frequency at which the output of a scattering system vanishes, corresponding to perfect absorption or anti-lasing conditions.

References

1. Dynamic switching from coherent perfect absorption to parametric amplification in a nonlinear spoof plasmonic waveguide. Nature Communications (2024).
2. Fibre-optic metadevice for all-optical signal modulation based on coherent absorption. Nature Communications (2018).
3. Coherent perfect absorption in deeply subwavelength films in the single-photon regime. Nature Communications (2015).
4. Optical analog of black and white gravitational holes. Advanced Photonics (2025).
5. A Lossless Sink Based on Complex Frequency Excitations. Advanced Science (2023).
6. Asymmetric phase modulation of light with parity-symmetry broken metasurfaces. Optica (2023).
7. Plasmonic nanoantennas as integrated coherent perfect absorbers on SOI waveguides for modulators and all-optical switches.. Optics Express (2013).
8. Coherent perfect absorption and transparency in a nanostructured graphene film. Optics Express (2014).
9. Tunable mid-infrared coherent perfect absorption in a graphene meta-surface. Scientific Reports (2015).