Blob Detection for Photonic Metasurface Designing: Angular and Spectral Control of Scattered Light

TL;DR

This paper presents a novel reverse-engineering method for designing correlated-disordered metasurfaces that achieve precise angular and spectral control of light scattering, validated through fabrication and simulations.

Contribution

It introduces a Fourier space tailoring and blob detection approach for metasurface design, enabling independent control over angular and spectral scattering properties.

Findings

Fabricated Au nanopillar ensembles match design predictions.

Simulations show independent tuning of spectral and angular responses.

Combining multiple metasurfaces expands control over scattering characteristics.

Abstract

Metasurfaces with precise spectral and angular control of light scattering are of growing interest for photonic applications requiring advanced photon management. Correlated disorder emerged as a promising route for angular control of light scattering, but most design approaches are computationally expensive or do not allow spectral tunability. Here, we introduce a reverse-engineering design approach for correlated-disordered metasurfaces based on tailoring the Fourier space and blob detection to create point distributions that are later "decorated" with individually designed nano-resonators or meta-atoms to tune the optical response for the desired functionality. We validate the control of the angular scattering by fabricating ensembles of Au nanopillars following our design and characterizing their angular scattering with Fourier microscopy. Using finite-difference time-domain simulations, we demonstrate how the choice of decorative unit tunes the spectral response, showcasing individual and independent control over light scattering in angular and spectral terms. Lastly, we expand the limits of our versatile approach by combining multiple metasurfaces in one, effectively adding their individual scattering characteristics. As such, we can address spectral and angular ranges independently, yielding a high degree of control of the scattering response.