Spatial engineering of the nonlinear susceptibility χ^((2)) in resonant metasurfaces offers a new degree of freedom in the design of the far-field response of second-harmonic generation(SHG). We demonstrate this by a...Spatial engineering of the nonlinear susceptibility χ^((2)) in resonant metasurfaces offers a new degree of freedom in the design of the far-field response of second-harmonic generation(SHG). We demonstrate this by applying electric field poling to lithium niobate(LN) thin films, which inverts the spontaneous polarization and thus the sign of χ^((2)). Metasurfaces fabricated in periodically poled LN films reveal the distinct influence of theχ^((2))-patterning on the spatial distribution of the second harmonic. This work is a first step toward far-field engineering of SHG in metasurfaces with electric field poling.展开更多
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 pro...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.展开更多
基金Freistaat Thüringen[Pro Excellence initiative(ACP2020),Quantum Hub Thuringia(2021 FGI 0043)]The European Union(METAFAST-899673-FETOPENH2020)+1 种基金Bundesministerium für Bildung und Forschung(13N14877,13N16108)Deutsche Forschungsgemeinschaft(407070005,CRC 1375 NOA 398816777,subprojects B2and C2,PE 1524/13-1,SE 2749/1-1,STA 1426/2-1)
文摘Spatial engineering of the nonlinear susceptibility χ^((2)) in resonant metasurfaces offers a new degree of freedom in the design of the far-field response of second-harmonic generation(SHG). We demonstrate this by applying electric field poling to lithium niobate(LN) thin films, which inverts the spontaneous polarization and thus the sign of χ^((2)). Metasurfaces fabricated in periodically poled LN films reveal the distinct influence of theχ^((2))-patterning on the spatial distribution of the second harmonic. This work is a first step toward far-field engineering of SHG in metasurfaces with electric field poling.
基金We thank Waltraud Gräf,Daniel Voigt,Michael Banasch,and Thomas Käsebier for help with the fabrication.Financial support by the German Research Foundation within the Emmy-Noether program and the SPP“Tailored Disorder”(STA 1426/1-1,STA 1426/2-1,PE 1524/10-2)is gratefully acknowledged.Part of this research was funded by the German Federal Ministry of Education and Research(BMBF)under the project identifiers 13N14147 and 03ZZ0434.
文摘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.
