Gradient Nonlinear Pancharatnam-Berry Metasurfaces

TL;DR

This paper introduces a novel nonlinear metasurface platform using Pancharatnam-Berry phase to control wavefronts for second-harmonic generation, enabling advanced beam shaping and polarization control with relaxed phase matching.

Contribution

It demonstrates a new approach to nonlinear wavefront control using Pancharatnam-Berry metasurfaces loaded with quantum well substrates, achieving high efficiency and local control.

Findings

Effective second-harmonic beam steering and focusing

Enhanced nonlinear response with relaxed phase matching

Unprecedented local wavefront control in thin devices

Abstract

We apply the Pancharatnam-Berry phase approach to plasmonic metasurfaces loaded by highly nonlinear multi-quantum well substrates, establishing a platform to control the nonlinear wavefront at will based on giant localized nonlinear effects. We apply this approach to design flat nonlinear metasurfaces for efficient second-harmonic radiation, including beam steering, focusing, and polarization manipulation. Our findings open a new direction for nonlinear optics, in which phase matching issues are relaxed, and an unprecedented level of local wavefront control is achieved over thin devices with giant nonlinear responses.