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arXiv · 2205.05926

Observation of Non-Vanishing Optical Helicity in Thermal Radiation from Symmetry-Broken Metasurfaces

Xueji Wang·Tyler Sentz·Sathwik Bharadwaj·Subir Ray·Yifan Wang·Dan Jiao·Limei Qi·Zubin Jacob
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Abstract

Spinning thermal radiation is a unique phenomenon observed in condensed astronomical objects including the Wolf-Rayet star EZ-CMa and the red degenerate star G99-47, due to existence of strong magnetic fields. Here, by designing symmetry-broken metasurfaces, we demonstrate that spinning thermal radiation with a non-vanishing optical helicity can be realized even without applying a magnetic field. We design non-vanishing optical helicity by engineering a dispersionless band which emits omnidirectional spinning thermal radiation, where our design reaches 39% of the fundamental limit. Our results firmly suggest metasurfaces can impart spin coherence in the incoherent radiation excited by thermal fluctuations. The symmetry-based design strategy also provides a general pathway for comprehensively controlling thermal radiation in its temporal and spin coherence.

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Xueji Wang, Tyler Sentz, Sathwik Bharadwaj, Subir Ray, Yifan Wang, Dan Jiao, Limei Qi, Zubin Jacob. 2022-05-12. Observation of Non-Vanishing Optical Helicity in Thermal Radiation from Symmetry-Broken Metasurfaces. https://doi.org/10.1126/sciadv.ade4203

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