Electromagnetic(EM)metamaterials represent a cutting-edge field that achieves anomalously macroscopic properties through artificial design and arrangement of microstructure arrays to freely manipulate EM fields and wa...Electromagnetic(EM)metamaterials represent a cutting-edge field that achieves anomalously macroscopic properties through artificial design and arrangement of microstructure arrays to freely manipulate EM fields and waves in desired ways.The unit cell of a microstructure array is also called a meta-atom,which can construct effective medium parameters that do not exist in traditional materials or are difficult to realize with traditional technologies.By deep integration with digital information,the meta-atom is evolved to a digital meta-atom,leading to the emergence of information metamaterials.Information metamaterials break the inherent barriers between the EM and digital domains,providing a physical platform for controlling EM waves and modulating digital information simultaneously.The concepts of meta-atoms and metamaterials are also introduced to high-frequency integrated circuit designs to address issues that cannot be solved by traditional methods,since lumped-parameter models become unsustainable at microscopic scales.By incorporating several meta-atoms to form a metachip,precise manipulation of the EM field distribution can be achieved at microscopic scales.In this perspective,we summarize the physical connotations and main classifications of meta-atoms and briefly discuss their future development trends.Through this article,we hope to draw more research attention to explore the potential values of meta-atoms,thereby opening up a broader stage for the in-depth development of metamaterials.展开更多
Flat optics have attracted interest for decades due to their flexibility in manipulating optical wave properties,which allows the miniaturization of bulky optical assemblies into integrated planar components.Recent ad...Flat optics have attracted interest for decades due to their flexibility in manipulating optical wave properties,which allows the miniaturization of bulky optical assemblies into integrated planar components.Recent advances in achromatic flat lenses have shown promising applications in various fields.However,it is a significant challenge for achromatic flat lenses with a high numerical aperture to simultaneously achieve broad bandwidth and expand the aperture sizes.Here,we present the zone division multiplex of the meta-atoms on a stepwise phase dispersion compensation(SPDC)layer to address the above challenge.In principle,the aperture size can be freely enlarged by increasing the optical thickness difference between the central and marginal zones of the SPDC layer,without the limit of the achromatic bandwidth.The SPDC layer also serves as the substrate,making the device thinner.Two achromatic flat lenses of 500 nm thickness with a bandwidth of 650–1000 nm are experimentally achieved:one with a numerical aperture of 0.9 and a radius of 20.1µm,and another with a numerical aperture of 0.7 and a radius of 30.0µm.To the best of our knowledge,they are the broadband achromatic flat lenses with highest numerical apertures,the largest aperture sizes and thinnest thickness reported so far.Microscopic imaging with a 1.10µm resolution has also been demonstrated by white light illumination,surpassing any previously reported resolution attained by achromatic metalenses and multi-level diffractive lenses.These unprecedented performances mark a substantial step toward practical applications of flat lenses.展开更多
In microwave communication systems,focusing and imaging have attracted widespread attention due to their application prospects in the information processing and communication fields.Most existing multi-channel focusin...In microwave communication systems,focusing and imaging have attracted widespread attention due to their application prospects in the information processing and communication fields.Most existing multi-channel focusing and imaging are implemented by interleaved metasurfaces.However,the disadvantages of their large size and low efficiency limit their practical applications in large-capacity and low-loss integrated systems.To solve these issues,here,we propose a non-interleaved polarization-frequency multiplexing metasurface for high-efficiency multi-channel focusing and imaging.The meta-atoms of the non-interleaved metasurface are composed of a metallic ground plate,two dielectric layers,a larger cross-shaped metal structure,and a smaller cross-shaped metal structure embedded by a circular metal aperture.By altering the size of two cross-shaped structures,the designed meta-atom can obtain the independent complete 2π phase coverage with high reflection efficiency at two different frequency ranges for two orthogonal linear polarization(LP)incidences,realizing polarization multiplexing and frequency multiplexing.Moreover,two types of metasurfaces based on the above meta-atoms are designed to realize multi-channel focusing and imaging with high efficiency.As a proof,the focusing metasurface is fabricated and measured,and the measured results are well consistent with simulated results.Therefore,the proposed scheme has the advantages of high efficiency,multi-channel,and compact size,which possesses broad application prospects in low-loss and multichannel communication integrated systems.展开更多
A new strategy has been presented to overcome the long-term dilemma of simultaneously achieving high numerical aperture,large aperture size,and broadband achromatism of flat lenses.A stepwise phase dispersion compensa...A new strategy has been presented to overcome the long-term dilemma of simultaneously achieving high numerical aperture,large aperture size,and broadband achromatism of flat lenses.A stepwise phase dispersion compensation(SPDC)layer is introduced as a substrate on which the meta-atoms are positioned.展开更多
基金supported by the Project on Frontier and Interdisciplinary Research Assessment,Academic Divisions of the Chinese Academy of Sciences(Grant No.XK2023XXA001)the National Natural Science Foundation of China(Grant Nos.62422106,62131007,62471109,and 62288101).
文摘Electromagnetic(EM)metamaterials represent a cutting-edge field that achieves anomalously macroscopic properties through artificial design and arrangement of microstructure arrays to freely manipulate EM fields and waves in desired ways.The unit cell of a microstructure array is also called a meta-atom,which can construct effective medium parameters that do not exist in traditional materials or are difficult to realize with traditional technologies.By deep integration with digital information,the meta-atom is evolved to a digital meta-atom,leading to the emergence of information metamaterials.Information metamaterials break the inherent barriers between the EM and digital domains,providing a physical platform for controlling EM waves and modulating digital information simultaneously.The concepts of meta-atoms and metamaterials are also introduced to high-frequency integrated circuit designs to address issues that cannot be solved by traditional methods,since lumped-parameter models become unsustainable at microscopic scales.By incorporating several meta-atoms to form a metachip,precise manipulation of the EM field distribution can be achieved at microscopic scales.In this perspective,we summarize the physical connotations and main classifications of meta-atoms and briefly discuss their future development trends.Through this article,we hope to draw more research attention to explore the potential values of meta-atoms,thereby opening up a broader stage for the in-depth development of metamaterials.
基金supported by the National Key R&D Program of China(No.2021YFA1400800)National Natural Science Foundation of China(Nos.12374363,12074444,and 11704421)+2 种基金Guangdong Basic and Applied Basic Research Foundation(No.2020B0301030009)Guangdong Provincial Natural Science Fund Projects(2024B1515040013)Guangdong Provincial Quantum Science Strategic Initiative(GDZX2306002,GDZX2206001)。
文摘Flat optics have attracted interest for decades due to their flexibility in manipulating optical wave properties,which allows the miniaturization of bulky optical assemblies into integrated planar components.Recent advances in achromatic flat lenses have shown promising applications in various fields.However,it is a significant challenge for achromatic flat lenses with a high numerical aperture to simultaneously achieve broad bandwidth and expand the aperture sizes.Here,we present the zone division multiplex of the meta-atoms on a stepwise phase dispersion compensation(SPDC)layer to address the above challenge.In principle,the aperture size can be freely enlarged by increasing the optical thickness difference between the central and marginal zones of the SPDC layer,without the limit of the achromatic bandwidth.The SPDC layer also serves as the substrate,making the device thinner.Two achromatic flat lenses of 500 nm thickness with a bandwidth of 650–1000 nm are experimentally achieved:one with a numerical aperture of 0.9 and a radius of 20.1µm,and another with a numerical aperture of 0.7 and a radius of 30.0µm.To the best of our knowledge,they are the broadband achromatic flat lenses with highest numerical apertures,the largest aperture sizes and thinnest thickness reported so far.Microscopic imaging with a 1.10µm resolution has also been demonstrated by white light illumination,surpassing any previously reported resolution attained by achromatic metalenses and multi-level diffractive lenses.These unprecedented performances mark a substantial step toward practical applications of flat lenses.
基金National Natural Science Foundation of China(62075052,6227419)National Key Research and Development Program of China(2024YFE0108300)+2 种基金Science and Technology Major Project of Guangxi,China(Gui Ke AA21077015,Gui Ke AA24263032)Science Foundation of the National Key Laboratory of Science and Technology on Advanced Composites in Special Environments(JCKYS2020603C009,6142905212711)Project of Innovative and Entrepreneurship Training Program for College Students in Heilongjiang Province(201810214105)。
文摘In microwave communication systems,focusing and imaging have attracted widespread attention due to their application prospects in the information processing and communication fields.Most existing multi-channel focusing and imaging are implemented by interleaved metasurfaces.However,the disadvantages of their large size and low efficiency limit their practical applications in large-capacity and low-loss integrated systems.To solve these issues,here,we propose a non-interleaved polarization-frequency multiplexing metasurface for high-efficiency multi-channel focusing and imaging.The meta-atoms of the non-interleaved metasurface are composed of a metallic ground plate,two dielectric layers,a larger cross-shaped metal structure,and a smaller cross-shaped metal structure embedded by a circular metal aperture.By altering the size of two cross-shaped structures,the designed meta-atom can obtain the independent complete 2π phase coverage with high reflection efficiency at two different frequency ranges for two orthogonal linear polarization(LP)incidences,realizing polarization multiplexing and frequency multiplexing.Moreover,two types of metasurfaces based on the above meta-atoms are designed to realize multi-channel focusing and imaging with high efficiency.As a proof,the focusing metasurface is fabricated and measured,and the measured results are well consistent with simulated results.Therefore,the proposed scheme has the advantages of high efficiency,multi-channel,and compact size,which possesses broad application prospects in low-loss and multichannel communication integrated systems.
文摘A new strategy has been presented to overcome the long-term dilemma of simultaneously achieving high numerical aperture,large aperture size,and broadband achromatism of flat lenses.A stepwise phase dispersion compensation(SPDC)layer is introduced as a substrate on which the meta-atoms are positioned.
