Metasurfaces are ultrathin optical elements that are highly promising for constructing lightweight and compact optical systems.For their practical implementation,it is imperative to maximize the metasurface efficiency...Metasurfaces are ultrathin optical elements that are highly promising for constructing lightweight and compact optical systems.For their practical implementation,it is imperative to maximize the metasurface efficiency.Topology optimization provides a pathway for pushing the limits of metasurface efficiency;however,topology optimization methods have been limited to the design of microscale devices due to the extensive computational resources that are required.We introduce a new strategy for optimizing large-area metasurfaces in a computationally efficient manner.By stitching together individually optimized sections of the metasurface,we can reduce the computational complexity of the optimization from high-polynomial to linear.As a proof of concept,we design and experimentally demonstrate large-area,high-numerical-aperture silicon metasurface lenses with focusing efficiencies exceeding 90%.These concepts can be generalized to the design of multifunctional,broadband diffractive optical devices and will enable the implementation of large-area,high-performance metasurfaces in practical optical systems.展开更多
The growing maturity of nanofabrication has ushered massive sophisticated optical structures available on a photonic chip.The integration of subwavelength-structured metasurfaces and metamaterials on the canonical bui...The growing maturity of nanofabrication has ushered massive sophisticated optical structures available on a photonic chip.The integration of subwavelength-structured metasurfaces and metamaterials on the canonical building block of optical waveguides is gradually reshaping the landscape of photonic integrated circuits,giving rise to numerous metawaveguides with unprecedented strength in controlling guided electromagnetic waves.Here,we review recent advances in meta-structured waveguides that synergize various functional subwavelength photonic architectures with diverse waveguide platforms,such as dielectric or plasmonic waveguides and optical fibers.Foundational results and representative applications are comprehensively summarized.Brief physical models with explicit design tutorials,either physical intuition-based design methods or computer algorithms-based inverse designs,are cataloged as well.We highlight how meta-optics can infuse new degrees of freedom to waveguide-based devices and systems,by enhancing light-matter interaction strength to drastically boost device performance,or offering a versatile designer media for manipulating light in nanoscale to enable novel functionalities.We further discuss current challenges and outline emerging opportunities of this vibrant field for various applications in photonic integrated circuits,biomedical sensing,artificial intelligence and beyond.展开更多
Epidermal electronic systems feature physical properties that approximate those of the skin,to enable intimate,long-lived skin interfaces for physiological measurements,human–machine interfaces and other applications...Epidermal electronic systems feature physical properties that approximate those of the skin,to enable intimate,long-lived skin interfaces for physiological measurements,human–machine interfaces and other applications that cannot be addressed by wearable hardware that is commercially available today.A primary challenge is power supply;the physical bulk,large mass and high mechanical modulus associated with conventional battery technologies can hinder efforts to achieve epidermal characteristics,and near-field power transfer schemes offer only a limited operating distance.Here we introduce an epidermal,farfield radio frequency(RF)power harvester built using a modularized collection of ultrathin antennas,rectifiers and voltage doublers.These components,separately fabricated and tested,can be integrated together via methods involving soft contact lamination.Systematic studies of the individual components and the overall performance in various dielectric environments highlight the key operational features of these systems and strategies for their optimization.The results suggest robust capabilities for battery-free RF power,with relevance to many emerging epidermal technologies.展开更多
Multifunctional metasurfaces based on wavelength-decoupled supercells are experimentally demonstrated,enabling new regimes of optical control for arbitrary orthogonal polarizations at different wavelengths.
We introduce an imaging system that can simultaneously record complete Mueller polarization responses for a set of wavelength channels in a single image capture.The division-of-focal-plane concept combines a multiplex...We introduce an imaging system that can simultaneously record complete Mueller polarization responses for a set of wavelength channels in a single image capture.The division-of-focal-plane concept combines a multiplexed illumination scheme based on Fourier optics together with an integrated telescopic light-field imaging system.Polarization-resolved imaging is achieved using broadband nanostructured plasmonic polarizers as functional pinhole apertures.The recording of polarization and wavelength information on the image sensor is highly interpretable.We also develop a calibration approach based on a customized neural network architecture that can produce calibrated measurements in real-time.As a proof-of-concept demonstration,we use our calibrated system to accurately reconstruct a thin film thickness map from a four-inch wafer.We anticipate that our concept will have utility in metrology,machine vision,computational imaging,and optical computing platforms.展开更多
基金supported by the U.S.Air Force under Award Number FA9550-18-1-0070the Office of Naval Research under Award Number N00014-16-1-2630+3 种基金the David and Lucile Packard Foundationsupported by the National Science Foundation(NSF)through an NSF Graduate Research Fellowshipsupported by the Department of Defense(DoD)through an NDSEG Research Fellowshipsupported by the National Science Foundation as part of the National Nanotechnology Coordinated Infrastructure under award ECCS-1542152.
文摘Metasurfaces are ultrathin optical elements that are highly promising for constructing lightweight and compact optical systems.For their practical implementation,it is imperative to maximize the metasurface efficiency.Topology optimization provides a pathway for pushing the limits of metasurface efficiency;however,topology optimization methods have been limited to the design of microscale devices due to the extensive computational resources that are required.We introduce a new strategy for optimizing large-area metasurfaces in a computationally efficient manner.By stitching together individually optimized sections of the metasurface,we can reduce the computational complexity of the optimization from high-polynomial to linear.As a proof of concept,we design and experimentally demonstrate large-area,high-numerical-aperture silicon metasurface lenses with focusing efficiencies exceeding 90%.These concepts can be generalized to the design of multifunctional,broadband diffractive optical devices and will enable the implementation of large-area,high-performance metasurfaces in practical optical systems.
基金Q.X.acknowledges support from National Natural Science Foundation of China(Grants Nos.62075113,61675114)S.S.is supported by National Key Research and Development Program of China(Nos.2020YFA0710101,2017YFA0303504)+8 种基金National Natural Science Foundation of China(11874118)Natural Science Foundation of Shanghai(18ZR1403400,20JC1414601)Fudan University-CIOMP Joint Fund(No.FC2018-008)M.Z.is supported by National Natural Science Foundation of China(61775069,61635004)J.A.F.is supported by Office of Naval Research(under Award No.N00014-20-1-2105)ARPA-E(under Award No.DE-AR0001212)Z.X.and X.Y.acknowledge support from National Natural Science Foundation of China(61935013,U1701661,61975133)the Natural Science Foundation of Guangdong Province(2020A1515011185)the Science and Technology Innovation Commission of Shenzhen(JCYJ20180507182035270,JCYJ20200109114018750).
文摘The growing maturity of nanofabrication has ushered massive sophisticated optical structures available on a photonic chip.The integration of subwavelength-structured metasurfaces and metamaterials on the canonical building block of optical waveguides is gradually reshaping the landscape of photonic integrated circuits,giving rise to numerous metawaveguides with unprecedented strength in controlling guided electromagnetic waves.Here,we review recent advances in meta-structured waveguides that synergize various functional subwavelength photonic architectures with diverse waveguide platforms,such as dielectric or plasmonic waveguides and optical fibers.Foundational results and representative applications are comprehensively summarized.Brief physical models with explicit design tutorials,either physical intuition-based design methods or computer algorithms-based inverse designs,are cataloged as well.We highlight how meta-optics can infuse new degrees of freedom to waveguide-based devices and systems,by enhancing light-matter interaction strength to drastically boost device performance,or offering a versatile designer media for manipulating light in nanoscale to enable novel functionalities.We further discuss current challenges and outline emerging opportunities of this vibrant field for various applications in photonic integrated circuits,biomedical sensing,artificial intelligence and beyond.
基金XF and YM acknowledge the support from the National Basic Research Program of China(Grant No.2015CB351900)the National Natural Science Foundation of China(Grant Nos.11402135 and 11320101001).
文摘Epidermal electronic systems feature physical properties that approximate those of the skin,to enable intimate,long-lived skin interfaces for physiological measurements,human–machine interfaces and other applications that cannot be addressed by wearable hardware that is commercially available today.A primary challenge is power supply;the physical bulk,large mass and high mechanical modulus associated with conventional battery technologies can hinder efforts to achieve epidermal characteristics,and near-field power transfer schemes offer only a limited operating distance.Here we introduce an epidermal,farfield radio frequency(RF)power harvester built using a modularized collection of ultrathin antennas,rectifiers and voltage doublers.These components,separately fabricated and tested,can be integrated together via methods involving soft contact lamination.Systematic studies of the individual components and the overall performance in various dielectric environments highlight the key operational features of these systems and strategies for their optimization.The results suggest robust capabilities for battery-free RF power,with relevance to many emerging epidermal technologies.
文摘Multifunctional metasurfaces based on wavelength-decoupled supercells are experimentally demonstrated,enabling new regimes of optical control for arbitrary orthogonal polarizations at different wavelengths.
基金supported by the Samsung Global Outreach Program and the Office of Naval Research under Award Number N00014-16-1-2630EW was supported by the Stanford Graduate Fellowship.Fabrication was performed in part at the Stanford Nanofabrication Facility(SNF)and the Stanford Nano Shared Facilities(SNSF)supported by the National Science Foundation as part of the National Nanotechnology Coordinated Infrastructure under award ECCS-1542152.
文摘We introduce an imaging system that can simultaneously record complete Mueller polarization responses for a set of wavelength channels in a single image capture.The division-of-focal-plane concept combines a multiplexed illumination scheme based on Fourier optics together with an integrated telescopic light-field imaging system.Polarization-resolved imaging is achieved using broadband nanostructured plasmonic polarizers as functional pinhole apertures.The recording of polarization and wavelength information on the image sensor is highly interpretable.We also develop a calibration approach based on a customized neural network architecture that can produce calibrated measurements in real-time.As a proof-of-concept demonstration,we use our calibrated system to accurately reconstruct a thin film thickness map from a four-inch wafer.We anticipate that our concept will have utility in metrology,machine vision,computational imaging,and optical computing platforms.
