Optical metasurfaces have become versatile platforms for manipulating the phase,amplitude,and polarization of light.A platform for achieving independent control over each of these properties,however,remains elusive du...Optical metasurfaces have become versatile platforms for manipulating the phase,amplitude,and polarization of light.A platform for achieving independent control over each of these properties,however,remains elusive due to the limited engineering space available when using a single-layer metasurface.For instance,multiwavelength metasurfaces suffer from performance limitations due to space filling constraints,while control over phase and amplitude can be achieved,but only for a single polarization.Here,we explore bilayer dielectric metasurfaces to expand the design space for metaoptics.The ability to independently control the geometry and function of each layer enables the development of multifunctional metaoptics in which two or more optical properties are independently designed.As a proof of concept,we demonstrate multiwavelength holograms,multiwavelength waveplates,and polarization-insensitive 3D holograms based on phase and amplitude masks.The proposed architecture opens a new avenue for designing complex flat optics with a wide variety of functionalities.展开更多
Over the last decades,the treatment of the large quantities of hypersaline wastewater generated by conventional industries,inland desalination,and fossil-fueled power plants has been an important economic issue and al...Over the last decades,the treatment of the large quantities of hypersaline wastewater generated by conventional industries,inland desalination,and fossil-fueled power plants has been an important economic issue and also an inescapable green issue.Here,we developed a versatile interfacial heating membrane with alternating utilization of electricity or solar energy for hypersaline water treat-ment.This hierarchical membrane functions both as a separation membrane and an interface heater,which can quickly(<0.1 s)convert electricity or solar energy into heat to evaporate the outermost layer of hypersaline water.For 10wt% hyper-saline water,the freshwater production rate can reach 16.8kg/m^(2)⋅h by applying a voltage of 10 V and 1.36 kg/m^(2)⋅h under 1-sun illumination.Moreover,it exhibits high electrochemical resistance to corrosion and therefore remains stable tack-ling hypersaline water(>5 wt%),with a high salt rejection rate of 99.99%.This system shows an efficient desalination strategy that can provide fresh water from brines for agriculture and industry,and even for daily life.展开更多
基金support received from the Office of Naval Research under award N00014-18-1-2563the National Science Foundation under award ECCS-1351334support received from the National Science Foundation under award DMR-1410940.
文摘Optical metasurfaces have become versatile platforms for manipulating the phase,amplitude,and polarization of light.A platform for achieving independent control over each of these properties,however,remains elusive due to the limited engineering space available when using a single-layer metasurface.For instance,multiwavelength metasurfaces suffer from performance limitations due to space filling constraints,while control over phase and amplitude can be achieved,but only for a single polarization.Here,we explore bilayer dielectric metasurfaces to expand the design space for metaoptics.The ability to independently control the geometry and function of each layer enables the development of multifunctional metaoptics in which two or more optical properties are independently designed.As a proof of concept,we demonstrate multiwavelength holograms,multiwavelength waveplates,and polarization-insensitive 3D holograms based on phase and amplitude masks.The proposed architecture opens a new avenue for designing complex flat optics with a wide variety of functionalities.
基金National Key R&D Program of China,Grant/Award Number:2018YFA0209500National Natural Science Foundation of China,Grant/Award Numbers:21621091,21975209,52025132。
文摘Over the last decades,the treatment of the large quantities of hypersaline wastewater generated by conventional industries,inland desalination,and fossil-fueled power plants has been an important economic issue and also an inescapable green issue.Here,we developed a versatile interfacial heating membrane with alternating utilization of electricity or solar energy for hypersaline water treat-ment.This hierarchical membrane functions both as a separation membrane and an interface heater,which can quickly(<0.1 s)convert electricity or solar energy into heat to evaporate the outermost layer of hypersaline water.For 10wt% hyper-saline water,the freshwater production rate can reach 16.8kg/m^(2)⋅h by applying a voltage of 10 V and 1.36 kg/m^(2)⋅h under 1-sun illumination.Moreover,it exhibits high electrochemical resistance to corrosion and therefore remains stable tack-ling hypersaline water(>5 wt%),with a high salt rejection rate of 99.99%.This system shows an efficient desalination strategy that can provide fresh water from brines for agriculture and industry,and even for daily life.
