Creating materials with time-variant properties is critical for breaking reciprocity that imposes fundamental limitations on wave propagation.However,it is challenging to realize efficient and ultrafast temporal modul...Creating materials with time-variant properties is critical for breaking reciprocity that imposes fundamental limitations on wave propagation.However,it is challenging to realize efficient and ultrafast temporal modulation in a photonic system.Here,leveraging both spatial and temporal phase manipulation offered by an ultrathin nonlinear metasurface,we experimentally demonstrated nonreciprocal light reflection at wavelengths around 860 nm.The metasurface,with travelling-wave modulation upon nonlinear Kerr building blocks,creates spatial phase gradient and multi-terahertz temporal phase wobbling,which leads to unidirectional photonic transitions in both the momentum and energy spaces.We observed completely asymmetric reflections in forward and backward light propagations over a large bandwidth around 5.77 THz within a sub-wavelength interaction length of 150 nm.Our approach highlights a potential means for creating miniaturized and integratable nonreciprocal optical components.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
The exploration of quantum inspired symmetries in optical systems has spawned promising physics and provided fertile ground for developing devices exhibiting exotic functionalities. Founded on the anti-parity–time (A...The exploration of quantum inspired symmetries in optical systems has spawned promising physics and provided fertile ground for developing devices exhibiting exotic functionalities. Founded on the anti-parity–time (APT)symmetry that is enabled by both spatial and temporal interplay between gain and loss,we demonstrate theoretically and numerically bi-color lasing in a single micro-ring resonator with spatiotemporal modulation along its azimuthal direction. In contrast to conventional multi-mode lasers that have mixed-frequency output,our laser exhibits stable,demultiplexed,tunable bi-color emission at different output ports. Our APT-symmetry-based laser may point out a new route for realizing compact on-chip coherent multi-color light sources.展开更多
基金partially supported from the Gordon and Betty Moore Foundation and the Penn State MRSEC,the Center for Nanoscale Science,under award number NSF DMR-1420620.
文摘Creating materials with time-variant properties is critical for breaking reciprocity that imposes fundamental limitations on wave propagation.However,it is challenging to realize efficient and ultrafast temporal modulation in a photonic system.Here,leveraging both spatial and temporal phase manipulation offered by an ultrathin nonlinear metasurface,we experimentally demonstrated nonreciprocal light reflection at wavelengths around 860 nm.The metasurface,with travelling-wave modulation upon nonlinear Kerr building blocks,creates spatial phase gradient and multi-terahertz temporal phase wobbling,which leads to unidirectional photonic transitions in both the momentum and energy spaces.We observed completely asymmetric reflections in forward and backward light propagations over a large bandwidth around 5.77 THz within a sub-wavelength interaction length of 150 nm.Our approach highlights a potential means for creating miniaturized and integratable nonreciprocal optical components.
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Moore Inventor Fellow award from the Gordon and Betty Moore FoundationNational Aeronautics and Space Administration Early Career Faculty Award (NASA ECF)(80NSSC17K0528)Penn State MRSEC,Center for Nanoscale Science (NSF DMR-1420620)。
文摘The exploration of quantum inspired symmetries in optical systems has spawned promising physics and provided fertile ground for developing devices exhibiting exotic functionalities. Founded on the anti-parity–time (APT)symmetry that is enabled by both spatial and temporal interplay between gain and loss,we demonstrate theoretically and numerically bi-color lasing in a single micro-ring resonator with spatiotemporal modulation along its azimuthal direction. In contrast to conventional multi-mode lasers that have mixed-frequency output,our laser exhibits stable,demultiplexed,tunable bi-color emission at different output ports. Our APT-symmetry-based laser may point out a new route for realizing compact on-chip coherent multi-color light sources.
