# Continuous polarization–wavelength mapping with nonlocal metasurfaces

## TL;DR

Researchers developed a new metasurface platform that can simultaneously and continuously control light's polarization and wavelength, enabling advanced optical applications.

## Contribution

A nonlocal metasurface platform is introduced to achieve continuous polarization–wavelength mapping beyond existing segmented designs.

## Key findings

- A nonlocal Jones matrix formalism and neural network enable spectrally resolved polarization shaping in mid-infrared.
- High-fidelity multicolor holography and polarization multiplexing are demonstrated with minimal crosstalk.
- The platform supports broadband achromatic imaging and arbitrary elliptical polarization control.

## Abstract

Simultaneous and continuous control over polarization and wavelength—two orthogonal and information-rich degrees of freedom—remains a central challenge in metasurface photonics, long hindered by intrinsic dispersion constraints and structural degeneracy. Here, we customize continuous polarization–wavelength mapping through a nonlocal metasurface platform that decouples birefringent evolution from structural dispersion. We achieve programmable, spectrally resolved polarization shaping across the broadband mid-infrared regime by introducing an equivalent nonlocal Jones matrix formalism and a dimension-interlaced vectorial diffraction neural network. This framework enables fully continuous and arbitrarily prescribed mapping across the joint polarization–wavelength space—beyond the capabilities of segmented or interleaved metasurface designs. We experimentally demonstrate non-degenerate multicolor vectorial holography, broadband achromatic imaging, and arbitrary elliptical polarization multiplexing with high fidelity and minimal crosstalk, maintaining strong channel isolation. Our results establish a scalable route toward continuous-domain photonic encoding, offering a powerful foundation for ultracompact optical communication, vectorial information encryption, and high-dimensional light-field processing.

Continuously spectral-encoded polarization shaping enabled by nonlocal metasurfaces