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arXiv · 2308.07998

Electrostatic Steering of Thermal Emission with Active Metasurface Control of Delocalized Modes

Joel Siegel·Shinho Kim·Margaret Fortman·Chenghao Wan·Mikhail A. Kats·Phillip W. C. Hon·Luke Sweatlock·Min Seok Jang·Victor Watson Brar
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Abstract

We theoretically describe and experimentally demonstrate a graphene-integrated metasurface structure that enables electrically-tunable directional control of thermal emission. This device consists of a dielectric slab that acts as a Fabry-Perot (F-P) resonator supporting long-range delocalized modes bounded on one side by an electrostatically tunable metal-graphene metasurface. By varying the Fermi level of the graphene, the accumulated phase of the F-P mode is shifted, which changes the direction of absorption and emission at a fixed frequency. We directly measure the frequency- and angle-dependent emissivity of the thermal emission from a fabricated device heated to 250$^{\circ}$. Our results show that electrostatic control allows the thermal emission at 6.61 $μ$m to be continuously steered over 16$^{\circ}$, with a peak emissivity maintained above 0.9. We analyze the dynamic behavior of the thermal emission steerer theoretically using a Fano interference model, and use the model to design optimized thermal steerer structures.

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Joel Siegel, Shinho Kim, Margaret Fortman, Chenghao Wan, Mikhail A. Kats, Phillip W. C. Hon, Luke Sweatlock, Min Seok Jang, Victor Watson Brar. 2024-04-22. Electrostatic Steering of Thermal Emission with Active Metasurface Control of Delocalized Modes. https://doi.org/10.1038/s41467-024-47229-0

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