Third-harmonic light polarization control in magnetically-resonant silicon metasurfaces

TL;DR

This paper demonstrates how silicon metasurfaces can be engineered to control the polarization states of third harmonic diffraction orders, enabling advanced wavefront manipulation at the nanoscale.

Contribution

It introduces a high-Q silicon metasurface design for third harmonic generation and analyzes the polarization of diffraction orders, revealing new control capabilities.

Findings

Diffraction orders exhibit diverse polarization states.

Polarization of nonlinear diffraction can be tailored.

Enhanced wavefront control through polarization engineering.

Abstract

Nonlinear metasurfaces have become prominent tools for controlling and engineering light at the nanoscale. Usually, the polarization of the total generated third harmonic is studied. However, diffraction orders may present different polarizations. Here, we design an high quality factor silicon metasurface for third harmonic generation and perform back focal plane imaging of the diffraction orders, which present a rich variety of polarization states. Our results demonstrate the possibility of tailoring the polarization of the generated nonlinear diffraction orders paving the way to a higher degree of wavefront control.