Observation of Non-Vanishing Optical Helicity in Thermal Radiation from Symmetry-Broken Metasurfaces
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.
- Publication:
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arXiv e-prints
- Pub Date:
- May 2022
- DOI:
- 10.48550/arXiv.2205.05926
- arXiv:
- arXiv:2205.05926
- Bibcode:
- 2022arXiv220505926W
- Keywords:
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- Physics - Optics;
- Physics - Applied Physics
- E-Print:
- Science Advances, Vol 9, Issue 4, 2023