Optical antennas are key components of an optical phased array system, enabling light coupling between the chip and the free space. In such systems, surface gratings are commonly used as antenna elements, which however suffer from a strong polarization sensitivity of their scattering angle and efficiency. A C2N team proposes a versatile approach to realize micro antennas based on surface gratings with a polarization insensitive behavior exploiting a subwavelength metamaterial in the silicon-on- insulator platform. In the experimental demonstration, the antenna successfully achieves the same diffraction angle of 10° for both TE and TM polarizations and an estimated scattering efficiency of -4 dB despite a very compact footprint of 6.4 μm x 2.9 μm. The difference in diffraction efficiency between the two polarizations remains smaller than 1 dB over a bandwidth of 31 nm.
References
Polarization independent silicon micro antenna based on a subwavelength metamaterial
Sarra Salhi1, Xiaochen Xin2, Daniel Benedikovič2,3 , Carlos Alonso-Ramos1, Laurent Vivien1, Delphine Marris-Morini1, Eric Cassan1, Winnie N. Ye2 & Daniele Melati1
Scientific Reports volume 15, Article number: 13276 (2025)
https://doi.org/10.1038/s41598-025-97833-3
Affiliations
1Centre de Nanosciences et de Nanotechnologies, Université Paris-Saclay, CNRS, 91120 Palaiseau, France
2Department of Electronics, Carleton University, Ottawa, ON K1S 5B6, Canada
3Dept. Multimedia and Information-Communication Technology, University of Zilina, 01026 Zilina, Slovakia
Key Words : Optical phased arrays, metamaterial, antennas, polarization insensitive
Contacts
daniele.melati@universite-paris-saclay.fr
sarra.salhi@universite-paris-saclay.fr
Figure : Scanning electron microscopy top view picture of the fabricated grating antenna
