Dielectric metasurfaces for distance measurements and three-dimensional imaging

Chunqi Jin,Stefan Fasold,René Berlich,Chengjun Zou,Mina Afsharnia,Dennis Arslan,Thomas Pertsch,Frank Setzpfandt,Isabelle Staude

doi:10.1117/1.ap.1.3.036001

Abstract

Ultrathin metasurfaces have shown the capability to influence all aspects of light propagation. This has made them promising options for replacing conventional bulky imaging optics while adding advantageous optical properties or functionalities. We demonstrate that such metasurfaces can also be applied for single-lens three-dimensional (3-D) imaging based on a specifically engineered point-spread function (PSF). Using Huygens’ metasurfaces with high transmission, we design and realize a phase mask that implements a rotating PSF for 3-D imaging. We experimentally characterize the properties of the realized double-helix PSF, finding that it can uniquely encode object distances within a wide range. Furthermore, we experimentally demonstrate wide-field depth retrieval within a 3-D scene, showing the suitability of metasurfaces to realize optics for 3-D imaging, using just a single camera and lens system.

Highlights

Metasurfaces, dense arrangements of subwavelengths scatterers in a plane, have been demonstrated to enable control of transmitted light in both amplitude and phase.[1]
Different regions of the phase mask can be identified by the different colors in the photograph. They result from the diffraction of the visible illumination light, which has a shorter wavelength than the periods of the metasurfaces
In addition to the DH-point-spread function (PSF), which mixes object information from adjacent locations, this is due to the rather large patch size needed for a robust cepstrum analysis

Summary

Introduction

Metasurfaces, dense arrangements of subwavelengths scatterers in a plane, have been demonstrated to enable control of transmitted light in both amplitude and phase.[1] metasurfaces manufactured solely from dielectric materials have a large application potential due to their many design degrees of freedom combined with negligible material losses,[2,3,4] especially compared to their plasmonic counterparts.[5] a number of different optical elements have been demonstrated, including holograms,[6,7,8,9,10] vortex-phase plates,[11,12,13] lenses,[7,14,15,16,17,18,19,20,21,22,23] and tunable functional elements.[24,25,26].

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Results

Conclusion