Gold-polymer hybrid metasurface for polarization-independent enhanced third harmonic generation in the ultraviolet

TL;DR

This study introduces a 3D gold-polymer hybrid metasurface that supports polarization-independent third harmonic generation, enabling efficient UV light production with potential applications in spectroscopy, data storage, and quantum photonics.

Contribution

The paper presents a novel three-dimensional metasurface design that achieves polarization-agnostic nonlinear optical responses, surpassing the limitations of traditional 2D metasurfaces.

Findings

Supports both TE and TM modes simultaneously

Enables efficient third-harmonic generation into UV range

Provides spectral tunability and polarization independence

Abstract

We present a combined experimental and theoretical study of nonlinear light-matter interactions in a three-dimensional gold-polymer hybrid metasurface. In contrast to conventional two-dimensional designs, which by symmetry may support either transverse electric (TE) or transverse magnetic (TM) polarization, our volumetric architecture accepts both TE and TM modes simultaneously, reflecting the dimensionality and versatility required by the photonic devices. The metasurface comprises a periodic lattice of gold nanostructures embedded in a dielectric polymer matrix, creating complex metal-dielectric interfaces that sustain tightly confined plasmonic resonances. When driven by ultrafast near-infrared pulses, these resonances concentrate optical energy at the nanoscale, enabling efficient third-harmonic generation and upconversion of visible light into the ultraviolet (UV) and deep-UV regimes with enhanced conversion efficiency. We perform spatial and temporal mapping of the nonlinear response under both TE and TM excitation. Our measurements reveal polarization-agnostic field enhancement and spectral tunability arising from the three-dimensional morphology-capabilities unattainable in planar metasurfaces, where two-dimensional symmetry inherently limits polarization flexibility and functional bandwidth. This 3D platform provides a flexible design toolbox for polarization-independent UV and deep-UV light sources. Potential applications include high-resolution UV spectroscopy, optical multiplexing, data storage, and emerging quantum photonic architectures. By establishing fundamental insights into three-dimensional nonlinear metasurface behavior, our work paves the way for next-generation reconfigurable, multi-polarization nanophotonic devices.