Selective Thermal Emission in Nanophotonic Systems

Selective thermal emission leverages nanophotonic design principles to tailor the spectrum, directionality and polarisation of thermal radiation beyond the limits of conventional blackbody behaviour. By integrating sub-wavelength structures—such as photonic crystals, metasurfaces and plasmonic resonators—researchers can engineer the electromagnetic local density of states and exploit resonant modes to achieve narrow linewidths, high temporal coherence and angular control. Dynamic modulation is realised through material phase transitions or electronic gating, enabling real-time tuning of emissivity. These capabilities underpin a host of applications, including thermophotovoltaic energy conversion, daytime radiative cooling, infrared sensing, thermal camouflage and secure information encryption. Recent advances demonstrate the global significance of nanophotonic thermal emitters in creating energy-efficient devices and novel infrared technologies.

Research from Nature Portfolio

Recent studies have introduced a flat-band design in distorted photonic lattices to achieve ultra-narrowband mid-infrared emission without angular dispersion, yielding a linewidth as low as a few tens of nanometres across a broad range of output angles. Stable high-temperature operation has been realised by coupling hot graphene electrons to photonic crystal nanocavities, where thermal decoupling of electrons from phonons produces tailored emission spectra at electron temperatures exceeding 2000 K while preserving substrate integrity. Foundational work on graphene plasmonic resonators demonstrated that electrostatic gating can modulate blackbody emission peaks in the mid-infrared, enabling dynamic control of both frequency and intensity through carrier-density variation.

Selective Thermal Emission in Nanophotonic Systems publication trend

The graph below shows the total number of articles in selective thermal emission in nanophotonic systems across all publications each year (not limited to Nature Index journals).

Technical terms

Emissivity: The efficiency with which a surface emits thermal radiation relative to a perfect blackbody at the same temperature.

Photonic crystal: A periodic arrangement of dielectric materials that creates photonic bandgaps and allows precise control over light propagation.

Plasmonic resonator: A nanostructure that supports collective electron oscillations at a metal–dielectric interface, enhancing local electromagnetic fields.

Metasurface: An ultrathin array of sub-wavelength scatterers engineered to manipulate the amplitude, phase and polarisation of incident light.

Local density of states: The number of available photonic modes at a given frequency and position, dictating emission characteristics of a thermal emitter.

References

1. Nanophotonic control of thermal radiation for energy applications [Invited].. Optics Express (2018).
2. Ultra-narrowband and rainbow-free mid-infrared thermal emitters enabled by a flat band design in distorted photonic lattices. Nature Communications (2024).
3. Thermal radiation control from hot graphene electrons coupled to a photonic crystal nanocavity. Nature Communications (2019).
4. Electronic modulation of infrared radiation in graphene plasmonic resonators. Nature Communications (2015).
5. Ultrabroadband Directional Tunable Thermal Emission Control Based on Vanadium Dioxide Photonic Structures. Advanced Science (2025).
6. Large circular dichroism in the emission from an incandescent metasurface. Optica (2023).
7. Thermal Metasurfaces: Complete Emission Control by Combining Local and Nonlocal Light-Matter Interactions. Physical Review X (2021).