Large circular dichroism in the emission by an incandescent metasurface

Anne Nguyen (1) , Jean-Paul Hugonin (1) , Anne-Lise Coutrot (1) , Enrique Garcia-Caurel (2) , Benjamin Vest (1) , Jean-Jacques Greffet (1)

1 Laboratoire Charles Fabry / Nanophotonique
2 LPICM - Laboratoire de physique des interfaces et des couches minces [Palaiseau]

Compact sources in the mid-wave infrared (MWIR) are needed for several applications ranging from spectroscopy to free-space communication. Ultra-thin incandescent metasurfaces are promising candidates, offering the possibility of tuning the emission spectrum, directivity and modulation speed. However, control over polarization remains a challenge, especially when it comes to emission of circularly polarized light. Here, emission of polarized MWIR radiation by a 700 nm thick incandescent chiral metasurface is reported. The degree of polarization is above 0.5 with degree of circular polarization of 0.38 at 5 µm. The metasurface is heated by Joule effect and its emission can be modulated beyond 10 MHz. This paves the way to detection techniques using polarization as an additional degree of freedom.

Domains: Optics [physics.optics]

Anne Nguyen, Jean-Paul Hugonin, Anne-Lise Coutrot, Enrique Garcia-Caurel, Benjamin Vest, et al.. Large circular dichroism in the emission by an incandescent metasurface. Optica, 2023, 10 (2), pp.232-238. ⟨10.1364/OPTICA.480292⟩. ⟨hal-03950184⟩