Decoupling optical function and geometrical form using conformal flexible dielectric metasurfaces

TL;DR

This paper introduces a method to decouple optical function from physical shape using flexible dielectric metasurfaces, enabling shape-constrained objects to achieve desired optical functionalities.

Contribution

The authors demonstrate a novel conformal metasurface approach that modifies optical properties independently of object geometry, allowing for versatile, multi-functional optical devices.

Findings

Cylindrical lenses with metasurfaces can focus light as aspherical lenses.

The conformal metasurface can be applied to arbitrarily shaped objects.

The approach operates at near-infrared wavelengths (915 nm).

Abstract

Physical geometry and optical properties of objects are correlated: cylinders focus light to a line, spheres to a point, and arbitrarily shaped objects introduce optical aberrations. Multi-functional components with decoupled geometrical form and optical function are needed when specific optical functionalities must be provided while the shapes are dictated by other considerations like ergonomics, aerodynamics, or esthetics. Here we demonstrate an approach for decoupling optical properties of objects from their physical shape using thin and flexible dielectric metasurfaces which conform to objects' surface and change their optical properties. The conformal metasurfaces are composed of silicon nano-posts embedded in a polymer substrate that locally modify near-infrared ($\it{\lambda}$ = 915 nm) optical wavefronts. As proof of concept, we show that cylindrical lenses covered with metasurfaces can be transformed to function as aspherical lenses focusing light to a point. The conformal metasurface concept is highly versatile for developing arbitrarily shaped multi-functional optical devices.