The next generation of smart imaging and vision systems will require compact and tunable optical computing hardware to perform high-speed and low-power image processing.These requirements are driving the development o...The next generation of smart imaging and vision systems will require compact and tunable optical computing hardware to perform high-speed and low-power image processing.These requirements are driving the development of computing metasurfaces to realize efficient front-end analog optical pre-processors,especially for edge detection capability.Yet,there is still a lack of reconfigurable or programmable schemes,which may drastically enhance the impact of these devices at the system level.Here,we propose and experimentally demonstrate a reconfigurable flat optical image processor using low-loss phase-change nonlocal metasurfaces.The metasurface is configured to realize different transfer functions in spatial frequency space,when transitioning the phase-change material between its amorphous and crystalline phases.This enables edge detection and bright field imaging modes on the same device.The metasurface is compatible with a large numerical aperture of~0.5,making it suitable for high resolution coherent optical imaging microscopy.The concept of phase-change reconfigurable nonlocal metasurfaces may enable emerging applications of artificial intelligence-assisted imaging and vision devices with switchable multitasking.展开更多
Metaoptics formed by ultrathin and planar building blocks enable compact and efficient optical devices that manipulate light at the nanoscale.The development of tunable metaoptics holds the promise of miniaturized and...Metaoptics formed by ultrathin and planar building blocks enable compact and efficient optical devices that manipulate light at the nanoscale.The development of tunable metaoptics holds the promise of miniaturized and efficient optical systems that can dynamically adapt to changing conditions or requirements,propelling innovations in fields ranging from telecommunication and imaging to quantum computing and sensing.Two-dimensional(2D)materials show strong promise in enabling tunable metaoptics due to their exceptional electronic and optical properties from the quantum confinement within the atomically thin layers.In this review,we discuss the recent advancements and challenges of 2D material-based tunable metaoptics in both linear and nonlinear regimes and provide an outlook for prospects in this rapidly advancing area.展开更多
Perfect vortices,recognized for their distinct ring profile that remains independent of the topological charge,present significant challenges in generation due to the precise control needed over both phase and polariz...Perfect vortices,recognized for their distinct ring profile that remains independent of the topological charge,present significant challenges in generation due to the precise control needed over both phase and polarization.In this work,we introduce and validate a new approach for generating these beams,allowing the selection of diffferent azimuthally-variant phase gradients and vector states,thereby enabling full control over the phase and polarization patterns of perfect vortices.Using dual-functional silicon metaoptics,we achieve the compact generation of a novel class of perfect vortices,termed azimuthally-variant perfect vector beams.The optical characterization of the generated beams,performed through a filtering method,confirms their intrinsic azimuthally-variant vectorial nature.These beams exhibit unique properties that promise valuable applications in optical tweezing,the manipulation of low-refractive-index particles,the trapping of cold atoms,and high-capacity communications.展开更多
基金supported by European Union’s Horizon 2020 research and innovation program(Grant No.101017237,PHOENICS Project)European Union’s EIC Pathfinder program(Grant No.101046878,HYBRAIN Project and No.101098717 RESPITE Project)+1 种基金funded in part by the UKRI[EP/T023899/1,EP/R001677/1,EP/W003341/1 and EP/W022931/1]funding from the Marie Sklodowska-Curie Individual Fellowship 101068089(METASCALE).
文摘The next generation of smart imaging and vision systems will require compact and tunable optical computing hardware to perform high-speed and low-power image processing.These requirements are driving the development of computing metasurfaces to realize efficient front-end analog optical pre-processors,especially for edge detection capability.Yet,there is still a lack of reconfigurable or programmable schemes,which may drastically enhance the impact of these devices at the system level.Here,we propose and experimentally demonstrate a reconfigurable flat optical image processor using low-loss phase-change nonlocal metasurfaces.The metasurface is configured to realize different transfer functions in spatial frequency space,when transitioning the phase-change material between its amorphous and crystalline phases.This enables edge detection and bright field imaging modes on the same device.The metasurface is compatible with a large numerical aperture of~0.5,making it suitable for high resolution coherent optical imaging microscopy.The concept of phase-change reconfigurable nonlocal metasurfaces may enable emerging applications of artificial intelligence-assisted imaging and vision devices with switchable multitasking.
基金financially supported by the National Research Foundation Singapore under CRP program(Grant No.NRFCRP26-2021-0004)the Agency for Science,Technology,and Research(A^(*)STAR)under the AME IRG Program(Grant Nos.A2083c0058 and A20E5c0084)+1 种基金the MTC Program(Grant No.M22L1b0110)he HBMS IAF-PP(Grant No.H19H6a0025)
文摘Metaoptics formed by ultrathin and planar building blocks enable compact and efficient optical devices that manipulate light at the nanoscale.The development of tunable metaoptics holds the promise of miniaturized and efficient optical systems that can dynamically adapt to changing conditions or requirements,propelling innovations in fields ranging from telecommunication and imaging to quantum computing and sensing.Two-dimensional(2D)materials show strong promise in enabling tunable metaoptics due to their exceptional electronic and optical properties from the quantum confinement within the atomically thin layers.In this review,we discuss the recent advancements and challenges of 2D material-based tunable metaoptics in both linear and nonlinear regimes and provide an outlook for prospects in this rapidly advancing area.
文摘Perfect vortices,recognized for their distinct ring profile that remains independent of the topological charge,present significant challenges in generation due to the precise control needed over both phase and polarization.In this work,we introduce and validate a new approach for generating these beams,allowing the selection of diffferent azimuthally-variant phase gradients and vector states,thereby enabling full control over the phase and polarization patterns of perfect vortices.Using dual-functional silicon metaoptics,we achieve the compact generation of a novel class of perfect vortices,termed azimuthally-variant perfect vector beams.The optical characterization of the generated beams,performed through a filtering method,confirms their intrinsic azimuthally-variant vectorial nature.These beams exhibit unique properties that promise valuable applications in optical tweezing,the manipulation of low-refractive-index particles,the trapping of cold atoms,and high-capacity communications.
