Wavelength-selective nonlinear wavefront control in resonant thin-film lithium niobate metasurfaces
Abstract
Nonlinear metasurfaces offer compact control over frequency conversion and wavefront shaping. However, existing approaches, often based on geometric phase, lack wavelength selectivity, resulting in static nonlinear responses. Here, we demonstrate a thin-film lithium niobate metasurface that enables spectrally selective shaping of second-harmonic generation through resonance-engineered phase control. The structure consists of two regions with distinct phase responses, realized via spectral tuning of Mie-type resonances. This design enables simultaneous frequency conversion and spatial mode shaping, transforming a Gaussian pump near 1100 nm into a first-order Hermite-Gaussian mode at 550 nm, while maintaining the pump profile. The demonstrated approach offers a pathway toward ultracompact and tunable components for nonlinear holography and related applications.
Keywords
Cite
@article{arxiv.2601.21382,
title = {Wavelength-selective nonlinear wavefront control in resonant thin-film lithium niobate metasurfaces},
author = {Madona Mekhael and Timo Stolt and Helena Weigand and Kiia Arola and Rachel Grange and Patrice Genevet and Mikko J. Huttunen},
journal= {arXiv preprint arXiv:2601.21382},
year = {2026}
}