# Polarization independent silicon micro antenna based on a subwavelength metamaterial

## TL;DR

This paper introduces a new silicon micro antenna that works equally well for all light polarizations, improving optical communication systems.

## Contribution

A polarization-insensitive silicon micro antenna is developed using subwavelength metamaterials for optical phased arrays.

## Key findings

- The antenna achieves a 10° diffraction angle for both TE and TM polarizations.
- The device maintains less than 1 dB efficiency difference across a 31 nm bandwidth.
- The compact design has a footprint of 6.4 μm x 2.9 μm with -4 dB scattering efficiency.

## Abstract

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. Here, we propose 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 \documentclass[12pt]{minimal}
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