Planar and ultrathin liquid crystal(LC)polarization optical elements have found promising applications in augmented reality(AR),virtual reality(VR),and photonic devices.In this paper,we give a comprehensive review on ...Planar and ultrathin liquid crystal(LC)polarization optical elements have found promising applications in augmented reality(AR),virtual reality(VR),and photonic devices.In this paper,we give a comprehensive review on the operation principles,device fabrication,and performance of these optical elements.Optical simulations methods for optimizing the device performance are discussed in detail.Finally,some potential applications of these devices in AR and VR systems are illustrated and analyzed.展开更多
Imaging through diffusers presents a challenging problem with various digital image reconstruction solutions demonstrated to date using computers.Here,we present a computer-free,all-optical image reconstruction method...Imaging through diffusers presents a challenging problem with various digital image reconstruction solutions demonstrated to date using computers.Here,we present a computer-free,all-optical image reconstruction method to see through random diffusers at the speed of light.Using deep learning,a set of transmissive diffractive surfaces are trained to all-optically reconstruct images of arbitrary objects that are completely covered by unknown,random phase diffusers.After the training stage,which is a one-time effort,the resulting diffractive surfaces are fabricated and form a passive optical network that is physically positioned between the unknown object and the image plane to all-optically reconstruct the object pattern through an unknown,new phase diffuser.We experimentally demonstrated this concept using coherent THz illumination and all-optically reconstructed objects distorted by unknown,random diffusers,never used during training.Unlike digital methods,all-optical diffractive reconstructions do not require power except for the illumination light.This diffractive solution to see through diffusers can be extended to other wavelengths,and might fuel various applications in biomedical imaging,astronomy,atmospheric sciences,oceanography,security,robotics,autonomous vehicles,among many others.展开更多
Let there be light-to change the world we want to be!Over the past several decades,and ever since the birth of the first laser,mankind has witnessed the development of the science of light,as light-based technologies ...Let there be light-to change the world we want to be!Over the past several decades,and ever since the birth of the first laser,mankind has witnessed the development of the science of light,as light-based technologies have revolutionarily changed our lives.Needless to say,photonics has now penetrated into many aspects of science and technology,turning into an important and dynamically changing field of increasing interdisciplinary interest.In this inaugural issue of eLight,we highlight a few emerging trends in photonics that we think are likely to have major impact at least in the upcoming decade,spanning from integrated quantum photonics and quantum computing,through topological/non-Hermitian photonics and topological insulator lasers,to AI-empowered nanophotonics and photonic machine learning.This Perspective is by no means an attempt to summarize all the latest advances in photonics,yet we wish our subjective vision could fuel inspiration and foster excitement in scientific research especially for young researchers who love the science of light.展开更多
Controlling electromagnetic waves and information simultaneously by information metasurfaces is of central importance in modern society.Intelligent metasurfaces are smart platforms to manipulate the wave-information-m...Controlling electromagnetic waves and information simultaneously by information metasurfaces is of central importance in modern society.Intelligent metasurfaces are smart platforms to manipulate the wave-information-matter interactions without manual intervention by synergizing engineered ultrathin structures with active devices and algorithms,which evolve from the passive composite materials for tailoring wave-matter interactions that cannot be achieved in nature.Here,we review the recent progress of intelligent metasurfaces in wave-information-matter controls by providing the historical background and underlying physical mechanisms.Then we explore the application of intelligent metasurfaces in developing novel wireless communication architectures,with particular emphasis on metasurface-modulated backscatter wireless communications.We also explore the wave-based computing by using the intelligent metasurfaces,focusing on the emerging research direction in intelligent sensing.Finally,we comment on the challenges and highlight the potential routes for the further developments of the intelligent metasurfaces for controls,communications and computing.展开更多
While conventional photodetectors can only measure light intensity,the vectorial light field contains much richer information,including polarization and spectrum,that are essential for numerous applications ranging fr...While conventional photodetectors can only measure light intensity,the vectorial light field contains much richer information,including polarization and spectrum,that are essential for numerous applications ranging from imaging to telecommunication.However,the simultaneous measurement of multi-dimensional light field information typically requires the multiplexing of dispersive or polarization-selective elements,leading to excessive system complexity.Here,we demonstrate a near-infrared spectropolarimeter based on an electrically-tunable liquid crystal metasurface.The tunable metasurface,which acts as an encoder of the vectorial light field,is tailored to support high-quality-factor guided-mode resonances with diverse and anisotropic spectral features,thus allowing the full Stokes parameters and the spectrum of the incident light to be computationally reconstructed with high fidelity.The concept of using a tunable metasurface for multi-dimensional light field encoding may open up new horizons for developing vectorial light field sensors with minimized size,weight,cost,and complexity.展开更多
Integrated silicon photonics has sparked a significant ramp-up of investment in both academia and industry as a scalable,power-efficient,and eco-friendly solution.At the heart of this platform is the light source,whic...Integrated silicon photonics has sparked a significant ramp-up of investment in both academia and industry as a scalable,power-efficient,and eco-friendly solution.At the heart of this platform is the light source,which in itself,has been the focus of research and development extensively.This paper sheds light and conveys our perspective on the current state-of-the-art in different aspects of application-driven on-chip silicon lasers.We tackle this from two perspectives:device-level and system-wide points of view.In the former,the different routes taken in integrating on-chip lasers are explored from different material systems to the chosen integration methodologies.Then,the discussion focus is shifted towards system-wide applications that show great prospects in incorporating photonic integrated circuits(PIC)with on-chip lasers and active devices,namely,optical communications and interconnects,optical phased array-based LiDAR,sensors for chemical and biological analysis,integrated quantum technologies,and finally,optical computing.By leveraging the myriad inherent attractive features of integrated silicon photonics,this paper aims to inspire further development in incorporating PICs with on-chip lasers in,but not limited to,these applications for substantial performance gains,green solutions,and mass production.展开更多
Optical metamaterials have presented an innovative method of manipulating light.Hyperbolic metamaterials have an extremely high anisotropy with a hyperbolic dispersion relation.They are able to support high-k modes an...Optical metamaterials have presented an innovative method of manipulating light.Hyperbolic metamaterials have an extremely high anisotropy with a hyperbolic dispersion relation.They are able to support high-k modes and exhibit a high density of states which produce distinctive properties that have been exploited in various applications,such as super-resolution imaging,negative refraction,and enhanced emission control.Here,state-of-the-art hyperbolic metamaterials are reviewed,starting from the fundamental principles to applications of artificially structured hyperbolic media to suggest ways to fuse natural two-dimensional hyperbolic materials.The review concludes by indicating the current challenges and our vision for future applications of hyperbolic metamaterials.展开更多
Nanophotonic platforms such as metasurfaces,achieving arbitrary phase profiles within ultrathin thickness,emerge as miniaturized,ultracompact and kaleidoscopic optical vortex generators.However,it is often required to...Nanophotonic platforms such as metasurfaces,achieving arbitrary phase profiles within ultrathin thickness,emerge as miniaturized,ultracompact and kaleidoscopic optical vortex generators.However,it is often required to segment or interleave independent sub-array metasurfaces to multiplex optical vortices in a single nano-device,which in turn affects the device’s compactness and channel capacity.Here,inspired by phyllotaxis patterns in pine cones and sunflowers,we theoretically prove and experimentally report that multiple optical vortices can be produced in a single compact phyllotaxis nanosieve,both in free space and on a chip,where one meta-atom may contribute to many vortices simultaneously.The time-resolved dynamics of on-chip interference wavefronts between multiple plasmonic vortices was revealed by ultrafast time-resolved photoemission electron microscopy.Our nature-inspired optical vortex generator would facilitate various vortex-related optical applications,including structured wavefront shaping,free-space and plasmonic vortices,and high-capacity information metaphotonics.展开更多
The wide application of optical spectroscopy makes miniaturized spectrometers with fundamental importance.The scalability,high-performance,low-cost,and small footprint are still contradicting each other and limiting t...The wide application of optical spectroscopy makes miniaturized spectrometers with fundamental importance.The scalability,high-performance,low-cost,and small footprint are still contradicting each other and limiting the applicability of miniaturized spectrometer for practical application.Here we propose a compact spectrometer that satisfies the four advantages.The device uses a fiber taper tip to generate complex leaky mode patterns within 1 mm length.The unique correspondence between the pattern and wavelength operates effectively for hundreds of nanometers spectral range while providing a spectral resolution around~1 pm.The integration of multiple taper tips enables hyperspectral imaging applications.The working range of our device can be further extended using different materials and detectors while keeping the similar architecture.展开更多
Metal halide perovskites(MHPs),emerging as innovative and promising semiconductor materials with prominent optoelectronic properties,has been pioneering a new era of light management(ranging from emission,absorption,m...Metal halide perovskites(MHPs),emerging as innovative and promising semiconductor materials with prominent optoelectronic properties,has been pioneering a new era of light management(ranging from emission,absorption,modulation,to transmission)for next-generation optoelectronic technology.Notably,the exploration of fundamental characteristics of MHPs and their devices is the main research theme during the past decade,while in the next decade,it will be primarily critical to promote their implantation in the next-generation optoelectronics.In this review,we first retrospect the historical research milestones of MHPs and their optoelectronic devices.Thereafter,we introduce the origin of the unique optoelectronic features of MHPs,based on which we highlight the tunability of these features via regulating the phase,dimensionality,composition,and geometry of MHPs.Then,we show that owing to the convenient property control of MHPs,various optoelectronic devices with target performance can be designed.At last,we emphasize on the revolutionary applications of MHPs-based devices on the existing optoelectronic systems.This review demonstrates the key role of MHPs played in the development of modern optoelectronics,which is expected to inspire the novel research directions of MHPs and promote the widespread applications of MHPs in the next-generation optoelectronics.展开更多
Brain-computer interfaces(BCIs),invasive or non-invasive,have projected unparalleled vision and promise for assisting patients in need to better their interaction with the surroundings.Inspired by the BCI-based rehabi...Brain-computer interfaces(BCIs),invasive or non-invasive,have projected unparalleled vision and promise for assisting patients in need to better their interaction with the surroundings.Inspired by the BCI-based rehabilitation technologies for nerve-system impairments and amputation,we propose an electromagnetic brain-computer-metasurface(EBCM)paradigm,regulated by human’s cognition by brain signals directly and non-invasively.We experimentally show that our EBCM platform can translate human’s mind from evoked potentials of P300-based electroencephalography to digital coding information in the electromagnetic domain non-invasively,which can be further processed and transported by an information metasurface in automated and wireless fashions.Directly wireless communications of the human minds are performed between two EBCM operators with accurate text transmissions.Moreover,several other proof-of-concept mind-control schemes are presented using the same EBCM platform,exhibiting flexibly-customized capabilities of information processing and synthesis like visual-beam scanning,wave modulations,and pattern encoding.展开更多
Structuring light emission from single-photon emitters(SPEs)in multiple degrees of freedom is of great importance for quantum information processing towards higher dimensions.However,traditional control of emission fr...Structuring light emission from single-photon emitters(SPEs)in multiple degrees of freedom is of great importance for quantum information processing towards higher dimensions.However,traditional control of emission from quantum light sources relies on the use of multiple bulky optical elements or nanostructured resonators with limited functionalities,constraining the potential of multi-dimensional tailoring.Here we introduce the use of an ultrathin polarisation-beam-splitting metalens for the arbitrary structuring of quantum emission at room temperature.Owing to the complete and independent polarisation and phase control at the single meta-atom level,the designed metalens enables simultaneous mapping of quantum emission from ultra-bright defects in hexagonal boron nitride and imprinting of an arbitrary wavefront onto orthogonal polarisation states of the sources.The hybrid quantum metalens enables simultaneous manipulation of multiple degrees of freedom of a quantum light source,including directionality,polarisation,and orbital angular momentum.This could unleash the full potential of solid-state SPEs for their use as high-dimensional quantum sources for advanced quantum photonic applications.展开更多
Privacy protection is a growing concern in the digital era,with machine vision techniques widely used throughout public and private settings.Existing methods address this growing problem by,e.g.,encrypting camera imag...Privacy protection is a growing concern in the digital era,with machine vision techniques widely used throughout public and private settings.Existing methods address this growing problem by,e.g.,encrypting camera images or obscuring/blurring the imaged information through digital algorithms.Here,we demonstrate a camera design that performs class-specific imaging of target objects with instantaneous all-optical erasure of other classes of objects.This diffractive camera consists of transmissive surfaces structured using deep learning to perform selective imaging of target classes of objects positioned at its input field-of-view.After their fabrication,the thin diffractive layers collectively perform optical mode filtering to accurately form images of the objects that belong to a target data class or group of classes,while instantaneously erasing objects of the other data classes at the output field-of-view.Using the same framework,we also demonstrate the design of class-specific permutation and class-specific linear transformation cameras,where the objects of a target data class are pixel-wise permuted or linearly transformed following an arbitrarily selected transformation matrix for all-optical class-specific encryption,while the other classes of objects are irreversibly erased from the output image.The success of class-specific diffractive cameras was experimentally demonstrated using terahertz(THz)waves and 3D-printed diffractive layers that selectively imaged only one class of the MNIST handwritten digit dataset,all-optically erasing the other handwritten digits.This diffractive camera design can be scaled to different parts of the electromagnetic spectrum,including,e.g.,the visible and infrared wavelengths,to provide transformative opportunities for privacy-preserving digital cameras and task-specific data-efficient imaging.展开更多
High-throughput computational imaging requires efficient processing algorithms to retrieve multi-dimensional and multi-scale information.In computational phase imaging,phase retrieval(PR)is required to reconstruct bot...High-throughput computational imaging requires efficient processing algorithms to retrieve multi-dimensional and multi-scale information.In computational phase imaging,phase retrieval(PR)is required to reconstruct both amplitude and phase in complex space from intensity-only measurements.The existing PR algorithms suffer from the tradeoff among low computational complexity,robustness to measurement noise and strong generalization on different modalities.In this work,we report an efficient large-scale phase retrieval technique termed as LPR.It extends the plug-and-play generalized-alternating-projection framework from real space to nonlinear complex space.The alternating projection solver and enhancing neural network are respectively derived to tackle the measurement formation and statistical prior regularization.This framework compensates the shortcomings of each operator,so as to realize high-fidelity phase retrieval with low computational complexity and strong generalization.We applied the technique for a series of computational phase imaging modalities including coherent diffraction imaging,coded diffraction pattern imaging,and Fourier ptychographic microscopy.Extensive simulations and experiments validate that the technique outperforms the existing PR algorithms with as much as 17dB enhancement on signal-to-noise ratio,and more than one order-of-magnitude increased running efficiency.Besides,we for the first time demonstrate ultralarge-scale phase retrieval at the 8K level(7680×4320 pixels)in minute-level time.展开更多
The use of optical tweezers to measure forces acting upon microscopic particles has revolutionised fields from material science to cell biology.However,despite optical control capabilities,this technology is highly co...The use of optical tweezers to measure forces acting upon microscopic particles has revolutionised fields from material science to cell biology.However,despite optical control capabilities,this technology is highly constrained by the material properties of the probe,and its use may be limited due to concerns about the effect on biological processes.Here we present a novel,optically controlled trapping method based on light-induced hydrodynamic flows.Specifically,we leverage optical control capabilities to convert a translationally invariant topological defect of a flow field into an attractor for colloids in an effectively one-dimensional harmonic,yet freely rotatable system.Circumventing the need to stabilise particle dynamics along an unstable axis,this novel trap closely resembles the isotropic dynamics of optical tweezers.Using magnetic beads,we explicitly show the existence of a linear force-extension relationship that can be used to detect femtoNewton-range forces with sensitivity close to the thermal limit.Our force measurements remove the need for laser-particle contact,while also lifting material constraints,which renders them a particu-larly interesting tool for the life sciences and engineering.展开更多
Optical technologies have been widely used in information security owing to its parallel and high-speed processing capability.However,the most critical problem with current optical encryption techniques is that the cy...Optical technologies have been widely used in information security owing to its parallel and high-speed processing capability.However,the most critical problem with current optical encryption techniques is that the cyphertext is linearly related with the plaintext,leading to the possibility that one can crack the system by solving a set of linear equations with only two cyphertext from the same encryption machine.Many efforts have been taken in the last decade to resolve the linearity issue,but none of these offers a true nonlinear solution.Inspired by the recent advance in spatial nonlinear optics,here we demonstrate a true nonlinear optical encryption technique.We show that,owing to the self-phase modulation effect of the photorefractive crystal,the proposed nonlinear optical image encryption technique is robust against the known plaintext attack based on phase retrieval.This opens up a new avenue for optical encryption in the spatial nonlinear domain.展开更多
The power of controlling objects with mind has captivated a popular fascination to human beings.One possible path is to employ brain signal collecting technologies together with emerging programmable metasurfaces(PM),...The power of controlling objects with mind has captivated a popular fascination to human beings.One possible path is to employ brain signal collecting technologies together with emerging programmable metasurfaces(PM),whose functions or operating modes can be switched or customized via on-site programming or pre-defined software.Nevertheless,most of existing PMs are wire-connected to users,manually-controlled and not real-time.Here,we propose the concept of remotely mind-controlled metasurface(RMCM)via brainwaves.Rather than DC voltage from power supply or AC voltages from signal generators,the metasurface is controlled by brainwaves collected in real time and transmitted wirelessly from the user.As an example,we demonstrated a RMCM whose scattering pattern can be altered dynamically according to the user’s brain waves via Bluetooth.The attention intensity information is extracted as the control signal and a mapping between attention intensity and scattering pattern of the metasurface is established.With such a framework,we experimentally demonstrated and verified a prototype of such metasurface system which can be remotely controlled by the user to modify its scattering pattern.This work paves a new way to intelligent metasurfaces and may find applications in health monitoring,5G/6G communications,smart sensors,etc.展开更多
Nanophotonic engineering provides an effective platform to manipulate thermal emission on-demand,enabling unprecedented heat management superior to conventional bulk materials.Amongst a plethora of nanophotonic struct...Nanophotonic engineering provides an effective platform to manipulate thermal emission on-demand,enabling unprecedented heat management superior to conventional bulk materials.Amongst a plethora of nanophotonic structures,symmetries play an important role in controlling radiative heat transfer in both near-field and far-field.In physics,broken symmetries generally increase the degree of freedom in a system,enriching the understanding of physical mechanisms and bringing many exciting opportunities for novel applications.In this review,we discussed the underlying physics and functionalities of nanophotonic structures with broken geometrical symmetries,engineered mode symmetries,and broken reciprocity for the control of thermal emission.We overview a variety of physical phenomena and interesting applications,and provide the outlook for future development.展开更多
The topological features of optical vortices have been opening opportunities for free-space and on-chip photonic technologies,e.g.,for multiplexed optical communications and robust information transport.In a parallel ...The topological features of optical vortices have been opening opportunities for free-space and on-chip photonic technologies,e.g.,for multiplexed optical communications and robust information transport.In a parallel but disjoint effort,polar anisotropic van der Waals nanomaterials supporting hyperbolic phonon polaritons(HP2s)have been leveraged to drastically boost light-matter interactions.So far HP2 studies have been mainly focusing on the control of their amplitude and scale features.Here we report the generation and observation of mid-infrared hyperbolic polariton vortices(HP2Vs)associated with reconfigurable topological charges.Spiral-shaped gold disks coated with a flake of hexagonal boron nitride are exploited to tailor spin-orbit interactions and realise deeply subwavelength HP2Vs.The complex interplay between excitation spin,spiral geometry and HP2 dispersion enables robust reconfigurability of the associated topological charges.Our results reveal unique opportunities to extend the application of HP2s into topological photonics,quantum information processing by integrating these phenomena with single-photon emitters,robust on-chip optical applications,sensing and nanoparticle manipulation.展开更多
Lanthanide-doped upconversion nanoparticles emerged recently as an attractive material platform underpinning a broad range of innovative applications such as optical cryptography,luminescent probes,and lasing.However,...Lanthanide-doped upconversion nanoparticles emerged recently as an attractive material platform underpinning a broad range of innovative applications such as optical cryptography,luminescent probes,and lasing.However,the intricate 4f-associated electronic transition in upconversion nanoparticles leads only to a weak photoluminescence intensity and unpolarized emission,hindering many applications that demand ultrabright and polarized light sources.Here,we present an effective strategy for achieving ultrabright and dual-band polarized upconversion photoluminescence.We employ resonant dielectric metasurfaces supporting high-quality resonant modes at dual upconversion bands enabling two-order-of-magnitude amplification of upconversion emissions.We demonstrate that dual-band resonances can be selectively switched on polarization,endowing cross-polarization controlled upconversion luminescence with ultra-high degrees of polarization,reaching approximately 0.86 and 0.91 at dual emission wavelengths of 540 and 660 nm,respectively.Our strategy offers an effective approach for enhancing photon upconversion processes paving the way towards efficient low-threshold polarization upconversion lasers.展开更多
文摘Planar and ultrathin liquid crystal(LC)polarization optical elements have found promising applications in augmented reality(AR),virtual reality(VR),and photonic devices.In this paper,we give a comprehensive review on the operation principles,device fabrication,and performance of these optical elements.Optical simulations methods for optimizing the device performance are discussed in detail.Finally,some potential applications of these devices in AR and VR systems are illustrated and analyzed.
基金The authors acknowledge the U.S.National Science Foundation and Fujikura.
文摘Imaging through diffusers presents a challenging problem with various digital image reconstruction solutions demonstrated to date using computers.Here,we present a computer-free,all-optical image reconstruction method to see through random diffusers at the speed of light.Using deep learning,a set of transmissive diffractive surfaces are trained to all-optically reconstruct images of arbitrary objects that are completely covered by unknown,random phase diffusers.After the training stage,which is a one-time effort,the resulting diffractive surfaces are fabricated and form a passive optical network that is physically positioned between the unknown object and the image plane to all-optically reconstruct the object pattern through an unknown,new phase diffuser.We experimentally demonstrated this concept using coherent THz illumination and all-optically reconstructed objects distorted by unknown,random diffusers,never used during training.Unlike digital methods,all-optical diffractive reconstructions do not require power except for the illumination light.This diffractive solution to see through diffusers can be extended to other wavelengths,and might fuel various applications in biomedical imaging,astronomy,atmospheric sciences,oceanography,security,robotics,autonomous vehicles,among many others.
基金support from the National Key R&D Program of China under Grant(No.2017YFA0303800).MS acknowledges support from the Israel Science Foundation.
文摘Let there be light-to change the world we want to be!Over the past several decades,and ever since the birth of the first laser,mankind has witnessed the development of the science of light,as light-based technologies have revolutionarily changed our lives.Needless to say,photonics has now penetrated into many aspects of science and technology,turning into an important and dynamically changing field of increasing interdisciplinary interest.In this inaugural issue of eLight,we highlight a few emerging trends in photonics that we think are likely to have major impact at least in the upcoming decade,spanning from integrated quantum photonics and quantum computing,through topological/non-Hermitian photonics and topological insulator lasers,to AI-empowered nanophotonics and photonic machine learning.This Perspective is by no means an attempt to summarize all the latest advances in photonics,yet we wish our subjective vision could fuel inspiration and foster excitement in scientific research especially for young researchers who love the science of light.
基金National Key Research and Development Program of China under Grant Nos.2021YFA1401002,2017YFA0700201,2017YFA0700202,and 2017YFA0700203,and the 111 Project under Grant No.111-2-05.
文摘Controlling electromagnetic waves and information simultaneously by information metasurfaces is of central importance in modern society.Intelligent metasurfaces are smart platforms to manipulate the wave-information-matter interactions without manual intervention by synergizing engineered ultrathin structures with active devices and algorithms,which evolve from the passive composite materials for tailoring wave-matter interactions that cannot be achieved in nature.Here,we review the recent progress of intelligent metasurfaces in wave-information-matter controls by providing the historical background and underlying physical mechanisms.Then we explore the application of intelligent metasurfaces in developing novel wireless communication architectures,with particular emphasis on metasurface-modulated backscatter wireless communications.We also explore the wave-based computing by using the intelligent metasurfaces,focusing on the emerging research direction in intelligent sensing.Finally,we comment on the challenges and highlight the potential routes for the further developments of the intelligent metasurfaces for controls,communications and computing.
基金National Natural Science Foundation of China(61975251,62135008)Guoqiang Institute,Tsinghua University。
文摘While conventional photodetectors can only measure light intensity,the vectorial light field contains much richer information,including polarization and spectrum,that are essential for numerous applications ranging from imaging to telecommunication.However,the simultaneous measurement of multi-dimensional light field information typically requires the multiplexing of dispersive or polarization-selective elements,leading to excessive system complexity.Here,we demonstrate a near-infrared spectropolarimeter based on an electrically-tunable liquid crystal metasurface.The tunable metasurface,which acts as an encoder of the vectorial light field,is tailored to support high-quality-factor guided-mode resonances with diverse and anisotropic spectral features,thus allowing the full Stokes parameters and the spectrum of the incident light to be computationally reconstructed with high fidelity.The concept of using a tunable metasurface for multi-dimensional light field encoding may open up new horizons for developing vectorial light field sensors with minimized size,weight,cost,and complexity.
基金supported by Intel(CG#62148533)Advanced Research Projects Agency-Energy(ARPA-E)(DE-AR0001039)+1 种基金the U.S.Department of Defense under AIM Photonics(Air Force contract FA8650-15-2-5220)the DARPA LUMOS(DARPA contract HR001120C0142).
文摘Integrated silicon photonics has sparked a significant ramp-up of investment in both academia and industry as a scalable,power-efficient,and eco-friendly solution.At the heart of this platform is the light source,which in itself,has been the focus of research and development extensively.This paper sheds light and conveys our perspective on the current state-of-the-art in different aspects of application-driven on-chip silicon lasers.We tackle this from two perspectives:device-level and system-wide points of view.In the former,the different routes taken in integrating on-chip lasers are explored from different material systems to the chosen integration methodologies.Then,the discussion focus is shifted towards system-wide applications that show great prospects in incorporating photonic integrated circuits(PIC)with on-chip lasers and active devices,namely,optical communications and interconnects,optical phased array-based LiDAR,sensors for chemical and biological analysis,integrated quantum technologies,and finally,optical computing.By leveraging the myriad inherent attractive features of integrated silicon photonics,this paper aims to inspire further development in incorporating PICs with on-chip lasers in,but not limited to,these applications for substantial performance gains,green solutions,and mass production.
基金POSCO-POSTECH-RIST Convergence Research Center program funded by POSCOPOSTECH-Samsung Semiconductor Research Center(IO201215-08187-01)funded by Samsung ElectronicsNational Research Foundation(NRF)grant(NRF-2019R1A2C3003129)funded by the Ministry of Science and ICT,Republic of Korea.
文摘Optical metamaterials have presented an innovative method of manipulating light.Hyperbolic metamaterials have an extremely high anisotropy with a hyperbolic dispersion relation.They are able to support high-k modes and exhibit a high density of states which produce distinctive properties that have been exploited in various applications,such as super-resolution imaging,negative refraction,and enhanced emission control.Here,state-of-the-art hyperbolic metamaterials are reviewed,starting from the fundamental principles to applications of artificially structured hyperbolic media to suggest ways to fuse natural two-dimensional hyperbolic materials.The review concludes by indicating the current challenges and our vision for future applications of hyperbolic metamaterials.
基金supported by the National Research Foundation,Prime Minister’s Office,Singapore under Competitive Research Program Award NRF-CRP22-2019-0006the grant(R-261-518-004-720)from Advanced Research and Technology Innovation Centre(ARTIC)+4 种基金the Deutsche Forschungsgemeinschaft(DFG,German Research Foundation)-Project-ID 278162697-SFB 1242ERC Advanced Grant Complex Plan,BMBF,DFG and BW-Stiftungthe Research Grants Council of Hong Kong(CRF Grant No.C6013-18G)the City University of Hong Kong(Project No.9610434)the support from A*STAR under its AME YIRG Grant(Award No.A2084c0172).
文摘Nanophotonic platforms such as metasurfaces,achieving arbitrary phase profiles within ultrathin thickness,emerge as miniaturized,ultracompact and kaleidoscopic optical vortex generators.However,it is often required to segment or interleave independent sub-array metasurfaces to multiplex optical vortices in a single nano-device,which in turn affects the device’s compactness and channel capacity.Here,inspired by phyllotaxis patterns in pine cones and sunflowers,we theoretically prove and experimentally report that multiple optical vortices can be produced in a single compact phyllotaxis nanosieve,both in free space and on a chip,where one meta-atom may contribute to many vortices simultaneously.The time-resolved dynamics of on-chip interference wavefronts between multiple plasmonic vortices was revealed by ultrafast time-resolved photoemission electron microscopy.Our nature-inspired optical vortex generator would facilitate various vortex-related optical applications,including structured wavefront shaping,free-space and plasmonic vortices,and high-capacity information metaphotonics.
基金National Natural Science Foundation of China(NSFC)(62222511,61905213)Natural Science Foundation of Zhejiang Province China(LR22F050006).
文摘The wide application of optical spectroscopy makes miniaturized spectrometers with fundamental importance.The scalability,high-performance,low-cost,and small footprint are still contradicting each other and limiting the applicability of miniaturized spectrometer for practical application.Here we propose a compact spectrometer that satisfies the four advantages.The device uses a fiber taper tip to generate complex leaky mode patterns within 1 mm length.The unique correspondence between the pattern and wavelength operates effectively for hundreds of nanometers spectral range while providing a spectral resolution around~1 pm.The integration of multiple taper tips enables hyperspectral imaging applications.The working range of our device can be further extended using different materials and detectors while keeping the similar architecture.
基金financially supported by the Natural Science Foundation of China(Grants 51972172,61705102,and 51802253)the China Postdoctoral Science Foundation(Grants 2021M692630)+6 种基金Natural Science Basic Research Plan in Shaanxi Province of China(2022JQ-629,2021JLM-43)the Joint Research Funds of Department of Science&Technology of Shaanxi Province and Northwestern Polytechnical University(2020GXLH-Z-007 and 2020GXLH-Z-014)Natural Science Foundation of Jiangsu Province for Distinguished Young Scholars,China(Grant BK20200034)the Innovation Project of Optics Valley Laboratory(OVL2021BG006)the Open Project Program of Wuhan National Laboratory for Optoelectronics(2021WNLOKF003)the Young 1000 Talents Global Recruitment Program of Chinathe Fundamental Research Funds for the Central Universities.
文摘Metal halide perovskites(MHPs),emerging as innovative and promising semiconductor materials with prominent optoelectronic properties,has been pioneering a new era of light management(ranging from emission,absorption,modulation,to transmission)for next-generation optoelectronic technology.Notably,the exploration of fundamental characteristics of MHPs and their devices is the main research theme during the past decade,while in the next decade,it will be primarily critical to promote their implantation in the next-generation optoelectronics.In this review,we first retrospect the historical research milestones of MHPs and their optoelectronic devices.Thereafter,we introduce the origin of the unique optoelectronic features of MHPs,based on which we highlight the tunability of these features via regulating the phase,dimensionality,composition,and geometry of MHPs.Then,we show that owing to the convenient property control of MHPs,various optoelectronic devices with target performance can be designed.At last,we emphasize on the revolutionary applications of MHPs-based devices on the existing optoelectronic systems.This review demonstrates the key role of MHPs played in the development of modern optoelectronics,which is expected to inspire the novel research directions of MHPs and promote the widespread applications of MHPs in the next-generation optoelectronics.
基金National Key Research and Development Program of China(2017YFA0700201,2017YFA0700202,and 2017YFA0700203)Major Project of Natural Science Foundation of Jiangsu Province(BK20212002)+9 种基金National Natural Science Foundation of China(61871127,61735010,61731010,61890544,61801117,61722106,61701107,61701108,61701246,61631007,61633010,61876064,62076099,61731010,and 11874142)State Key Laboratory of Millimeter Waves,Southeast University,China(K201924)Fundamental Research Funds for the Central Universities(2242018R30001)111 Project(111-2-05)Fund for International Cooperation and Exchange of National Natural Science Foundation of China(61761136007)Key R&D Program of Guangdong Province(2018B030339001)Key Realm R&D Program of Guangzhou(202007030007)Guangdong Basic and Applied Basic Research Foundation(2019A1515011773)Pearl River S&T Nova Program of Guangzhou(201906010043)C.-W.Q.acknowledges the financial support from the grant R-261-518-004-720 from Advanced Research and Technology Innovation Centre(ARTIC)。
文摘Brain-computer interfaces(BCIs),invasive or non-invasive,have projected unparalleled vision and promise for assisting patients in need to better their interaction with the surroundings.Inspired by the BCI-based rehabilitation technologies for nerve-system impairments and amputation,we propose an electromagnetic brain-computer-metasurface(EBCM)paradigm,regulated by human’s cognition by brain signals directly and non-invasively.We experimentally show that our EBCM platform can translate human’s mind from evoked potentials of P300-based electroencephalography to digital coding information in the electromagnetic domain non-invasively,which can be further processed and transported by an information metasurface in automated and wireless fashions.Directly wireless communications of the human minds are performed between two EBCM operators with accurate text transmissions.Moreover,several other proof-of-concept mind-control schemes are presented using the same EBCM platform,exhibiting flexibly-customized capabilities of information processing and synthesis like visual-beam scanning,wave modulations,and pattern encoding.
基金supported by Australian Research Council(CE200100010,DE220101085,DP220102152)the Office of Naval Research Global(N62909-22-1-2028)(I.A.)+5 种基金the POSCO-POSTECH-RIST Convergence Research Center program funded by POSCOthe Basic Science grant(SSTF-BA2102-05)funded by the Samsung Science and Technology Foundationthe National Research Foundation(NRF)grant(NRF-2022M3C1A3081312)funded by the Ministry of Science and ICT(MSIT)of the Korean governmentthe NRF Sejong Science fellowship(NRF-RS-2023-00209560)funded by the MSIT of Korea governmentthe Institute of Information&Communications Technology Planning&Evaluation(IITP)grant(No.2019-0-01906,the POSTECH Artificial Intelligence Graduate School program)funded by the MSIT of the Korean government,and the POSTECH PIURI fellowshipthe POSTECH Alchemist fellowship.
文摘Structuring light emission from single-photon emitters(SPEs)in multiple degrees of freedom is of great importance for quantum information processing towards higher dimensions.However,traditional control of emission from quantum light sources relies on the use of multiple bulky optical elements or nanostructured resonators with limited functionalities,constraining the potential of multi-dimensional tailoring.Here we introduce the use of an ultrathin polarisation-beam-splitting metalens for the arbitrary structuring of quantum emission at room temperature.Owing to the complete and independent polarisation and phase control at the single meta-atom level,the designed metalens enables simultaneous mapping of quantum emission from ultra-bright defects in hexagonal boron nitride and imprinting of an arbitrary wavefront onto orthogonal polarisation states of the sources.The hybrid quantum metalens enables simultaneous manipulation of multiple degrees of freedom of a quantum light source,including directionality,polarisation,and orbital angular momentum.This could unleash the full potential of solid-state SPEs for their use as high-dimensional quantum sources for advanced quantum photonic applications.
基金The Ozcan Research Group at UCLA acknowledges the support of ONR(Grant#N00014-22-1-2016)Jarrahi Research Group at UCLA acknowledges the support of the Department of Energy(Grant#DE-SC0016925).
文摘Privacy protection is a growing concern in the digital era,with machine vision techniques widely used throughout public and private settings.Existing methods address this growing problem by,e.g.,encrypting camera images or obscuring/blurring the imaged information through digital algorithms.Here,we demonstrate a camera design that performs class-specific imaging of target objects with instantaneous all-optical erasure of other classes of objects.This diffractive camera consists of transmissive surfaces structured using deep learning to perform selective imaging of target classes of objects positioned at its input field-of-view.After their fabrication,the thin diffractive layers collectively perform optical mode filtering to accurately form images of the objects that belong to a target data class or group of classes,while instantaneously erasing objects of the other data classes at the output field-of-view.Using the same framework,we also demonstrate the design of class-specific permutation and class-specific linear transformation cameras,where the objects of a target data class are pixel-wise permuted or linearly transformed following an arbitrarily selected transformation matrix for all-optical class-specific encryption,while the other classes of objects are irreversibly erased from the output image.The success of class-specific diffractive cameras was experimentally demonstrated using terahertz(THz)waves and 3D-printed diffractive layers that selectively imaged only one class of the MNIST handwritten digit dataset,all-optically erasing the other handwritten digits.This diffractive camera design can be scaled to different parts of the electromagnetic spectrum,including,e.g.,the visible and infrared wavelengths,to provide transformative opportunities for privacy-preserving digital cameras and task-specific data-efficient imaging.
基金supported by the National Natural Science Foundation of China(Nos.61971045,61827901,61991451)National Key R&D Program(Grant No.2020YFB0505601)Fundamental Research Funds for the Central Universities(Grant No.3052019024).
文摘High-throughput computational imaging requires efficient processing algorithms to retrieve multi-dimensional and multi-scale information.In computational phase imaging,phase retrieval(PR)is required to reconstruct both amplitude and phase in complex space from intensity-only measurements.The existing PR algorithms suffer from the tradeoff among low computational complexity,robustness to measurement noise and strong generalization on different modalities.In this work,we report an efficient large-scale phase retrieval technique termed as LPR.It extends the plug-and-play generalized-alternating-projection framework from real space to nonlinear complex space.The alternating projection solver and enhancing neural network are respectively derived to tackle the measurement formation and statistical prior regularization.This framework compensates the shortcomings of each operator,so as to realize high-fidelity phase retrieval with low computational complexity and strong generalization.We applied the technique for a series of computational phase imaging modalities including coherent diffraction imaging,coded diffraction pattern imaging,and Fourier ptychographic microscopy.Extensive simulations and experiments validate that the technique outperforms the existing PR algorithms with as much as 17dB enhancement on signal-to-noise ratio,and more than one order-of-magnitude increased running efficiency.Besides,we for the first time demonstrate ultralarge-scale phase retrieval at the 8K level(7680×4320 pixels)in minute-level time.
基金We thank Iain Patten for valuable discussions on the structure and layout of the manuscript.IDS kindly acknowledges funding from the Life grant by Volkswagen Foundation(Grant No.92772).
文摘The use of optical tweezers to measure forces acting upon microscopic particles has revolutionised fields from material science to cell biology.However,despite optical control capabilities,this technology is highly constrained by the material properties of the probe,and its use may be limited due to concerns about the effect on biological processes.Here we present a novel,optically controlled trapping method based on light-induced hydrodynamic flows.Specifically,we leverage optical control capabilities to convert a translationally invariant topological defect of a flow field into an attractor for colloids in an effectively one-dimensional harmonic,yet freely rotatable system.Circumventing the need to stabilise particle dynamics along an unstable axis,this novel trap closely resembles the isotropic dynamics of optical tweezers.Using magnetic beads,we explicitly show the existence of a linear force-extension relationship that can be used to detect femtoNewton-range forces with sensitivity close to the thermal limit.Our force measurements remove the need for laser-particle contact,while also lifting material constraints,which renders them a particu-larly interesting tool for the life sciences and engineering.
基金National Natural Science Foundation of China(61991452,62061136005)Sino-German Center(GZ1391).
文摘Optical technologies have been widely used in information security owing to its parallel and high-speed processing capability.However,the most critical problem with current optical encryption techniques is that the cyphertext is linearly related with the plaintext,leading to the possibility that one can crack the system by solving a set of linear equations with only two cyphertext from the same encryption machine.Many efforts have been taken in the last decade to resolve the linearity issue,but none of these offers a true nonlinear solution.Inspired by the recent advance in spatial nonlinear optics,here we demonstrate a true nonlinear optical encryption technique.We show that,owing to the self-phase modulation effect of the photorefractive crystal,the proposed nonlinear optical image encryption technique is robust against the known plaintext attack based on phase retrieval.This opens up a new avenue for optical encryption in the spatial nonlinear domain.
基金National Natural Science Foundation of China under Grant Nos.61971435,62101588,62101589National Key Research and Development Program of China(Grant No.:SQ2017YFA0700201)+1 种基金C.-W.Q.is supported by a grant(R-261-518-004-720|A-0005947-16-00)from Advanced Research and Technology Innovation Centre(ARTIC)in National University of Singapore.
文摘The power of controlling objects with mind has captivated a popular fascination to human beings.One possible path is to employ brain signal collecting technologies together with emerging programmable metasurfaces(PM),whose functions or operating modes can be switched or customized via on-site programming or pre-defined software.Nevertheless,most of existing PMs are wire-connected to users,manually-controlled and not real-time.Here,we propose the concept of remotely mind-controlled metasurface(RMCM)via brainwaves.Rather than DC voltage from power supply or AC voltages from signal generators,the metasurface is controlled by brainwaves collected in real time and transmitted wirelessly from the user.As an example,we demonstrated a RMCM whose scattering pattern can be altered dynamically according to the user’s brain waves via Bluetooth.The attention intensity information is extracted as the control signal and a mapping between attention intensity and scattering pattern of the metasurface is established.With such a framework,we experimentally demonstrated and verified a prototype of such metasurface system which can be remotely controlled by the user to modify its scattering pattern.This work paves a new way to intelligent metasurfaces and may find applications in health monitoring,5G/6G communications,smart sensors,etc.
基金S.F.acknowledges the support of the US Department of Energy(grant no.DE-FG02-07ER46426)W.L.acknowledges the support of the National Natural Science Foundation of China(grant nos.62134009,62121005)Development Program of the Science and Technology of Jilin Province(20200802001GH).
文摘Nanophotonic engineering provides an effective platform to manipulate thermal emission on-demand,enabling unprecedented heat management superior to conventional bulk materials.Amongst a plethora of nanophotonic structures,symmetries play an important role in controlling radiative heat transfer in both near-field and far-field.In physics,broken symmetries generally increase the degree of freedom in a system,enriching the understanding of physical mechanisms and bringing many exciting opportunities for novel applications.In this review,we discussed the underlying physics and functionalities of nanophotonic structures with broken geometrical symmetries,engineered mode symmetries,and broken reciprocity for the control of thermal emission.We overview a variety of physical phenomena and interesting applications,and provide the outlook for future development.
基金Office of Naval Research(Grant No.N00014-19-1-2011)Vannevar Bush Faculty Fellowship,Air Force Office of Scientific Research MURI program,A*STAR AME Young Individual Research Grant(YIRG,No.A2084c0172)+4 种基金National Research Foundation Singapore(CRP22-2019-0006)Advanced Research and Technology Innovation Centre(No.R-261-518-004-720)National Science Foundation under Grant No.2044281Elemental Strategy Initiative conducted by MEXT,Japan,Grant Number JPMXP0112101001JSPS KAKENHI Grant Number JP20H00354。
文摘The topological features of optical vortices have been opening opportunities for free-space and on-chip photonic technologies,e.g.,for multiplexed optical communications and robust information transport.In a parallel but disjoint effort,polar anisotropic van der Waals nanomaterials supporting hyperbolic phonon polaritons(HP2s)have been leveraged to drastically boost light-matter interactions.So far HP2 studies have been mainly focusing on the control of their amplitude and scale features.Here we report the generation and observation of mid-infrared hyperbolic polariton vortices(HP2Vs)associated with reconfigurable topological charges.Spiral-shaped gold disks coated with a flake of hexagonal boron nitride are exploited to tailor spin-orbit interactions and realise deeply subwavelength HP2Vs.The complex interplay between excitation spin,spiral geometry and HP2 dispersion enables robust reconfigurability of the associated topological charges.Our results reveal unique opportunities to extend the application of HP2s into topological photonics,quantum information processing by integrating these phenomena with single-photon emitters,robust on-chip optical applications,sensing and nanoparticle manipulation.
基金supporting by national Key R&D Program of China(2021YFB2802003,2022YFB3607300)the China Postdoctoral Science Foundation funded project(No.2022M711241)+1 种基金National Natural Science Foundation of China(NSFC)(62075084)the Guangdong Basic and Applied Basic Research Foundation(2022B1515020004).
文摘Lanthanide-doped upconversion nanoparticles emerged recently as an attractive material platform underpinning a broad range of innovative applications such as optical cryptography,luminescent probes,and lasing.However,the intricate 4f-associated electronic transition in upconversion nanoparticles leads only to a weak photoluminescence intensity and unpolarized emission,hindering many applications that demand ultrabright and polarized light sources.Here,we present an effective strategy for achieving ultrabright and dual-band polarized upconversion photoluminescence.We employ resonant dielectric metasurfaces supporting high-quality resonant modes at dual upconversion bands enabling two-order-of-magnitude amplification of upconversion emissions.We demonstrate that dual-band resonances can be selectively switched on polarization,endowing cross-polarization controlled upconversion luminescence with ultra-high degrees of polarization,reaching approximately 0.86 and 0.91 at dual emission wavelengths of 540 and 660 nm,respectively.Our strategy offers an effective approach for enhancing photon upconversion processes paving the way towards efficient low-threshold polarization upconversion lasers.
