Electro-optical modulation of light polarization in a nonlocal lithium niobate metasurface

TL;DR

This paper demonstrates a lithium niobate metasurface capable of efficient electro-optic modulation of light polarization at telecommunication wavelengths, using high-Q resonances to achieve significant polarization control in a compact device.

Contribution

It introduces a novel LiNbO3 metasurface design employing high-Q quasi-bound states to enhance electro-optic polarization modulation, a significant advancement over previous approaches.

Findings

Achieved 5% variation in Stokes parameters at 1 MHz

Demonstrated 3-degree polarization ellipse rotation

Validated potential for compact, high-efficiency electro-optic devices

Abstract

We report the experimental realization of a LiNbO3 metasurface for electro-optic modulation of light polarization in the telecommunication band. High-Q quasi-bound states in the continuum are emploied to enhance the modulation of amplitude and phase of an impinging beam by a driving electric field, leading to efficient polarization rotation and conversion. We quantified modulation effects under a CMOS-compatible bias at 1 MHz frequency, achieving a variation of 5% in the Stokes parameters and a variation of the polarization ellipse angles of about 3{\deg} for the transmitted light. These results demonstrate that dynamic polarization and phase modulation can be attained in a compact platform, highlighting the potential of high-Q resonant LiNbO3 metasurfaces for enhanced light-matter interaction in subwavelength electro-optic devices.