Nonlinear interferometry with infrared metasurfaces

TL;DR

This paper introduces a novel nonlinear interferometry method for characterizing infrared metasurfaces using visible light components, enabling broadband manipulation and precise phase measurement of IR optical elements.

Contribution

The study presents a new quantum interferometry technique for IR metasurface characterization using accessible visible light components, simplifying the process.

Findings

Successful implementation of nonlinear interferometry for IR metasurface characterization.

Demonstration of broadband visible beam manipulation using a single IR metasurface.

Potential for quantum interferometry to advance optical element analysis.

Abstract

The optical elements comprised of sub-diffractive light scatterers, or metasurfaces, hold a promise to reduce the footprint and unfold new functionalities of optical devices. A particular interest is focused on metasurfaces for manipulation of phase and amplitude of light beams. Characterisation of metasurfaces can be performed using interferometry, which, however, may be cumbersome, specifically in the infrared (IR) range. Here, we realise a new method for characterising IR metasurfaces based on nonlinear interference, which uses accessible components for visible light. Correlated IR and visible photons are launched into a nonlinear interferometer so that the phase profile, imposed by the metasurface on the IR photons, modifies the interference at the visible photon wavelength. Furthermore, we show that this concept can be used for broadband manipulation of the intensity profile of a visible beam using a single IR metasurface. Our method unfolds the potential of quantum interferometry for the characterization of advanced optical elements.