Non-linear interferometry with infrared metasurfaces

Anna V Paterova,Tobias W W Mass,Arseniy I Kuznetsov,Leonid A Krivitsky,Egor Khaidarov,Dmitry A Kalashnikov,Hongzhi Yang,Ramón Paniagua-Domínguez

doi:10.1515/nanoph-2021-0011

Abstract

AbstractThe 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 metasurfaces operating in the telecom IR range using accessible components for visible light. Correlated IR and visible photons are launched into a non-linear 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.

Highlights

The optical elements comprised of subdiffractive light scatterers, or metasurfaces, hold a promise to reduce the footprint and unfold new functionalities of optical devices
Correlated IR and visible photons are launched into a non-linear interferometer so that the phase profile, imposed by the metasurface on the IR photons, modifies the interference at the visible photon
Planar optical elements based on sub-wavelength light scatterers, referred to as metasurfaces, have gained significant interest over the last few years

Summary

Introduction

Planar optical elements based on sub-wavelength light scatterers, referred to as metasurfaces, have gained significant interest over the last few years. We develop a new approach for characterisation of metasurfaces, and non-local manipulation of the angular momentum of single photons, based on the nonlinear interference of correlated photons, referred to as induced coherence [24, 25] This method allows assessing the sample properties in the challenging for detection and broadband IR range by using an accessible light source and a photodetector for visible or near-infrared (NIR) light. This is a practical and economical advantage of our experiment with respect to the alternative non-linear methods [15,16,17,18], which would require the use of expensive tuneable lasers Another exciting feature of our experiment is that a single metasurface in the IR range can ‘virtually’ shape the visible beam at the few-photon level at multiple wavelengths.

Metasurface design

Non-linear interferometer

IR metasurfaces characterized by visible light

Numerical simulations

Experimental realization