The Bessel-like vector vortex beam(BlVVB)has gained increasing significance across numerous applications.However,its practical application is restricted by manufacturing difficulties and polarization manipulation.Thus...The Bessel-like vector vortex beam(BlVVB)has gained increasing significance across numerous applications.However,its practical application is restricted by manufacturing difficulties and polarization manipulation.Thus,the ability to manipulate its degrees of freedom is highly desirable.In this paper,the full-domain polarization modulation of BlVVB within a hot atomic ensemble has been investigated.We begin with the theoretical analysis of the resonant magneto-optical effect of atoms with a horizontal linear-polarized beam and experimentally demonstrate precise manipulation of the polarization state across the entire domain of the BlVVB,achieving an error margin of less than 3°at various cross-sectional points.Our study provides a novel approach for the modulation of BlVVB based on atomic media,which holds potential applications in sensitive vector magnetometers,optical communications,and signal processing.展开更多
The vector vortex beam(VVB)has attracted significant attention due to its intrinsic diversity of information and has found great applications in both classical and quantum communications.However,a VVB is unavoidably a...The vector vortex beam(VVB)has attracted significant attention due to its intrinsic diversity of information and has found great applications in both classical and quantum communications.However,a VVB is unavoidably affected by atmospheric turbulence(AT)when it propagates through the free-space optical communication environment,which results in detection errors at the receiver.In this paper,we propose a VVB classification scheme to detect VVBs with continuously changing polarization states under AT,where a diffractive deep neural network(DDNN)is designed and trained to classify the intensity distribution of the input distorted VVBs,and the horizontal direction of polarization of the input distorted beam is adopted as the feature for the classification through the DDNN.The numerical simulations and experimental results demonstrate that the proposed scheme has high accuracy in classification tasks.The energy distribution percentage remains above 95%from weak to medium AT,and the classification accuracy can remain above 95%for various strengths of turbulence.It has a faster convergence and better accuracy than that based on a convolutional neural network.展开更多
The perfect hybrid vector vortex beam(PHVVB)with helical phase wavefront structure has aroused significant concern in recent years,as its beam waist does not expand with the topological charge(TC).In this work,we inve...The perfect hybrid vector vortex beam(PHVVB)with helical phase wavefront structure has aroused significant concern in recent years,as its beam waist does not expand with the topological charge(TC).In this work,we investigate the spatial quantum coherent modulation effect with PHVVB based on the atomic medium,and we observe the absorption characteristic of the PHVVB with different TCs under variant magnetic fields.We find that the transmission spectrum linewidth of PHVVB can be effectively maintained regardless of the TC.Still,the width of transmission peaks increases slightly as the beam size expands in hot atomic vapor.This distinctive quantum coherence phenomenon,demonstrated by the interaction of an atomic medium with a hybrid vector-structured beam,might be anticipated to open up new opportunities for quantum coherence modulation and accurate magnetic field measurement.展开更多
Focused vector vortex beams(VVBs)offer significant potential for applications in nonlinear effects,quantum optics,and communications due to their symmetric intensity patterns,phase singularities,and structured polariz...Focused vector vortex beams(VVBs)offer significant potential for applications in nonlinear effects,quantum optics,and communications due to their symmetric intensity patterns,phase singularities,and structured polarization profiles.Nevertheless,the emerging frontier of dynamically tunable VVBs in the THz regime faces critical limitations in conventional static metasurface implementations,hindering their full potential for advanced photonic applications.In this work,we propose and demonstrate a design strategy,which employs dielectric cascaded metasurfaces to generate VVBs with tunable characteristics through mechanical twisting.To achieve this,LayerⅠis constructed from birefringent silicon pillars with rectangular configurations,enabling independent encoding of orthogonal circularly polarized channels via spin-decoupled phasing techniques,while LayerⅡis composed of cylindrical silicon pillars with polarization-maintaining properties to control the focal length.The generation and modulation of VVBs are achieved by mechanically adjusting the relative angles between these two layers,allowing for dynamic tuning of the beam's properties.Experimentally,we further present the accurate generation of first-and second-order focused VVBs with a high focusing efficiency(>12.9%),consistent with theoretical predictions.Moreover,the system exhibited continuous focal length tuning across 26λ-10.4λby rotating the layers from 90°to 240°,achieving a 42.8%modulation depth,while maintaining radial symmetry,as confirmed by an absolute percentage error analysis(<9.8%).The demonstrated mechanical tuning mechanism provides a practical pathway toward adaptive THz photonic devices,bridging critical gaps in real-world applications ranging from polarization-encoded communications to depthresolved biomedical imaging.展开更多
In this Letter,by exploiting the spin-to-orbital angular momentum conversion capability and the polarization selectivity characteristic of cholesteric liquid crystal planar optical elements,an approach of combing two ...In this Letter,by exploiting the spin-to-orbital angular momentum conversion capability and the polarization selectivity characteristic of cholesteric liquid crystal planar optical elements,an approach of combing two cholesteric liquid crystal layers with opposite handedness and independent surface patterns is proposed and investigated for generating arbitrary vector vortex beams on the hybrid-order Poincarésphere.Furthermore,the intensity profiles and polarization distributions of typical vector vortex beams are experimentally demonstrated and analyzed,which shows good agreement with the theoretical prediction.The approach also suggests its advantages of operating light in the polychromatic spectral region of Bragg reflection.Our method presents a simple and direct way of phase and polarization manipulation,which also provides promising opportunities for developing advanced applications in structured light,high-resolution imaging,and information processing.展开更多
Toroidal multipole is a special current distribution that has many different characteristics from electric multipole and magnetic multipole distributions.Because of its special properties,the toroidal dipole is a rese...Toroidal multipole is a special current distribution that has many different characteristics from electric multipole and magnetic multipole distributions.Because of its special properties,the toroidal dipole is a research hotspot in the field of metamaterials and nanophotonics.However,the low scattering of the toroidal dipole moment makes its excitation a challenging task.At present,there are relatively few studies on its specific engineering applications.In this paper,by slotting in the rectangular cavity,the excitation of an equivalent toroidal dipole is successfully achieved over a wide frequency range of 53-58 GHz.Results indicate that under the action of the toroidal dipole,the TE_(10)mode electromagnetic waves transmitted in the rectangular waveguide are converted into vector beams and are radiated outwards.Further adjusting the spatial distribution of the magnetic dipoles in the toroidal dipoles yields results that indicate that the resonance mode in the slot is still dominated by the magnetic toroidal dipole moment,and the electromagnetic waves radiating outward are vortex beams carrying vector polarization.The scattered energy of each dipole moment inside the antenna is calculated.This calculation verifies that the mass of the vector beam and vector vortex beam is closely related to the toroidal dipole supported by this antenna.The proposed structure can be applied to explorations in vortex filtering,in photon entanglement,and in the photonic spin Hall effect.展开更多
Vector vortex beams(VVBs), novel structured optical fields that combine the polarization properties of vector beams and phase characteristics of vortex beams, have garnered widespread attention in the photonics commun...Vector vortex beams(VVBs), novel structured optical fields that combine the polarization properties of vector beams and phase characteristics of vortex beams, have garnered widespread attention in the photonics community. Capitalizing on recently developed metasurfaces, miniaturized VVB generators with advanced properties have been implemented. However,metasurface-empowered VVB generators remain static and can only generate one pre-designed structured light. Here, we propose a kind of phase change metasurface for tunable vector beam generation by utilizing anisotropic Ge2Sb2Se4Te1(GSST) unit cells with tunable phase retardation when GSST transits between two different phase states. By properly rotating the orientations of the tunable GSST unit structures that transit between quarter-wave plates and half-wave plates, we can effectively transform incident plane waves into vector beams with distinct topological charges and polarization states.When GSST is in the amorphous state, the designed metasurface can transmit circularly polarized light into VVBs. In the crystalline state, the same GSST metasurface converts linearly polarized light into second-order radially polarized(RP) and azimuthally polarized(AP) beams. Our phase-change metasurface paves the way for precise control over the polarization patterns and vortex characteristics of beams, thereby enabling the exact manipulation of beam structures through the alteration of their phase states.展开更多
Scattering phenomena affect light propagation through any kind of medium from free space to biological tissues.Finding appropriate strategies to increase the robustness to scattering is the common requirement in devel...Scattering phenomena affect light propagation through any kind of medium from free space to biological tissues.Finding appropriate strategies to increase the robustness to scattering is the common requirement in developing both communication protocols and imaging systems.Recently,structured light has attracted attention due to its seeming scattering resistance in terms of transmissivity and spatial behavior.Moreover,correlation between optical polarization and orbital angular momentum(OAM),which characterizes the so-called vector vortex beams(VVBs)states,seems to allow for the preservation of the polarization pattern.We extend the analysis by investigating both the spatial features and the polarization structure of vectorial optical vortexes propagating in scattering media with different concentrations.Among the observed features,we find a sudden swift decrease in contrast ratio for Gaussian,OAM,and VVB modes for concentrations of the adopted scattering media exceeding 0.09%.Our analysis provides a more general and complete study on the propagation of structured light in dispersive and scattering media.展开更多
We propose theoretically and verify experimentally a compact optical configuration to directly generate arbitrary vector vortex beams on a hybrid-order Poincare sphere with good flexibility and high efficiency based o...We propose theoretically and verify experimentally a compact optical configuration to directly generate arbitrary vector vortex beams on a hybrid-order Poincare sphere with good flexibility and high efficiency based on a reflective phase-only liquid crystal spatial light modulator （LC-SLM）. The conversion system, consisting of an LC-SLM and a quarter-wave plate, can be considered a flexible dielectric metasurface to simultaneously modulate inhomogeneous polarization and helical phase-front. This approach has some advantages, including a simple experimental setup, good flexibility, and high efficiency. superposition existing in the conventional method are potential applications in many advanced domains. Orthogonally polarized modes alignment and an explicit not necessary in the proposed method, which exhibits展开更多
We propose theoretically and verify experimentally a method of combining a q-plate and a spiral phase plate to generate arbitrary vector vortex beams on a hybrid-order Poincaré sphere. We demonstrate that a vecto...We propose theoretically and verify experimentally a method of combining a q-plate and a spiral phase plate to generate arbitrary vector vortex beams on a hybrid-order Poincaré sphere. We demonstrate that a vector vortex beam can be decomposed into a vector beam and a vortex, whereby the generation can be realized by sequentially using a q-plate and a spiral phase plate. The generated vector beam, vortex, and vector vortex beam are verified and show good agreement with the prediction. Another advantage that should be pointed out is that the spiral phase plate and q-plate are both fabricated on silica substrates, suggesting the potential possibility to integrate the two structures on a single plate. Based on a compact method of transmissive-type transformation, our scheme may have potential applications in future integrated optical devices.展开更多
The performance breakthroughs of some stealth materials have benefited from incorporating biomimetic concepts,and the design ideas of wave-absorbing metamaterials have been greatly broadened.How-ever,stealth materials...The performance breakthroughs of some stealth materials have benefited from incorporating biomimetic concepts,and the design ideas of wave-absorbing metamaterials have been greatly broadened.How-ever,stealth materials developed based on a single biological structure still have limitations regarding overall performance and design freedom.Herein,a dual-structure element combination model with a butterfly-wing porous structure and moth-eye raised structure arranged in an orderly manner is estab-lished.Carbonyl iron and polyurethane are mixed as wave absorbents,and the model is utilized to make a biomimetic metamaterial(CSMA),which has an absorption rate of more than 90%at 6.07-18 GHz,achieving broadband effective absorption.It has been verified that the two biostructures designed after an ordered arrangement show synergistic effects in the combined model,and the cooperation between the structures induces the formation of current vector vortices,which are able to induce microwave losses to broaden the effective absorbing bandwidth.Further,the model has the combined application performance of polarization insensitivity,strong stability of oblique incidence,and low bistatic RCS.Such a thought based on the combination of multiple components provides an effective strategy for the design of broadband-absorbing metamaterials.展开更多
The unique phase profile and polarization distribution of the vector vortex beam(VVB)have been a subject of increasing interest in classical and quantum optics.The development of higher-order Poincarésphere(HOPS)...The unique phase profile and polarization distribution of the vector vortex beam(VVB)have been a subject of increasing interest in classical and quantum optics.The development of higher-order Poincarésphere(HOPS)and hybrid-order Poincarésphere(HyOPS)has provided a systematic description of VVB.However,the generation of arbitrary VVBs on a HOPS and a HyOPS via a metasurface lacks a unified design framework,despite numerous reported approaches.We present a unified design framework incorporating all design parameters(e.g.,focal lengths and orders)of arbitrary HOPS and HyOPS beams into a single equation.In proof-of-concept experiments,we experimentally demonstrated four metasurfaces to generate arbitrary beams on the fifth-order HOPS(nonfocused and tightly focused,NA 0.89),0-2 order,and 0-1 order HyOPS.We showed HOPS beams’propagation and focusing properties,the superresolution focusing characteristics of the first-order cylindrical VVBs,and the different focusing properties of integerorder and fractional-order cylindrical VVBs.The simplicity and feasibility of the proposed design framework make it a potential catalyst for arbitrary VVBs using metasurfaces in applications of optical imaging,communication,and optical trapping.展开更多
The rotational Doppler effect holds significant potential for remote sensing of rotating objects due to its real-time performance and non-contact advantages.A single-ring beam is used to measure rotation speed.To enha...The rotational Doppler effect holds significant potential for remote sensing of rotating objects due to its real-time performance and non-contact advantages.A single-ring beam is used to measure rotation speed.To enhance the signal-to-noise ratio and measure additional parameters,multiple rings are introduced in the context of a rotational Doppler effect.However,the interference between these rings poses a challenge for multitasking detection applications.In this study,cross-polarization superposition was applied to generate an ultra-dense vector perfect vortex beam that exhibited sensitivity to spatial position and object size,and flexibility in designing topological charge combinations for generating frequency combs.A proof-of-principle experiment was conducted to demonstrate its capability in improving the signal-to-noise ratio,and accurately perceiving both the radius of rotation and radial size.An ultra-dense vector perfect vortex beam provides a general strategy for beam construction and the multi-parameter perception of rotating objects,thereby enabling potential applications in the measurement of velocity gradient measurement of fluids.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant Nos.12033007,61801458,12103058,12203058,12074309,and 61875205)the Key Project of Frontier Science Research of the Chinese Academy of Sciences(Grant No.QYZDB-SSW-SLH007)+2 种基金the Strategic Priority Research Program of CAS(Grant No.XDC07020200)the Youth Innovation Promotion Association,CAS(Grant Nos.2021408,2022413,and 2023425)the Research on Highly Sensitive Long-Wave Receiver Based on Rydberg Atoms(Grant No.1P2024000059)。
文摘The Bessel-like vector vortex beam(BlVVB)has gained increasing significance across numerous applications.However,its practical application is restricted by manufacturing difficulties and polarization manipulation.Thus,the ability to manipulate its degrees of freedom is highly desirable.In this paper,the full-domain polarization modulation of BlVVB within a hot atomic ensemble has been investigated.We begin with the theoretical analysis of the resonant magneto-optical effect of atoms with a horizontal linear-polarized beam and experimentally demonstrate precise manipulation of the polarization state across the entire domain of the BlVVB,achieving an error margin of less than 3°at various cross-sectional points.Our study provides a novel approach for the modulation of BlVVB based on atomic media,which holds potential applications in sensitive vector magnetometers,optical communications,and signal processing.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.62375140 and 62001249)the Open Research Fund of National Laboratory of Solid State Microstructures(Grant No.M36055).
文摘The vector vortex beam(VVB)has attracted significant attention due to its intrinsic diversity of information and has found great applications in both classical and quantum communications.However,a VVB is unavoidably affected by atmospheric turbulence(AT)when it propagates through the free-space optical communication environment,which results in detection errors at the receiver.In this paper,we propose a VVB classification scheme to detect VVBs with continuously changing polarization states under AT,where a diffractive deep neural network(DDNN)is designed and trained to classify the intensity distribution of the input distorted VVBs,and the horizontal direction of polarization of the input distorted beam is adopted as the feature for the classification through the DDNN.The numerical simulations and experimental results demonstrate that the proposed scheme has high accuracy in classification tasks.The energy distribution percentage remains above 95%from weak to medium AT,and the classification accuracy can remain above 95%for various strengths of turbulence.It has a faster convergence and better accuracy than that based on a convolutional neural network.
基金Project supported by the Youth Innovation Promotion Association CASState Key Laboratory of Transient Optics and Photonics Open Topics (Grant No. SKLST202222)
文摘The perfect hybrid vector vortex beam(PHVVB)with helical phase wavefront structure has aroused significant concern in recent years,as its beam waist does not expand with the topological charge(TC).In this work,we investigate the spatial quantum coherent modulation effect with PHVVB based on the atomic medium,and we observe the absorption characteristic of the PHVVB with different TCs under variant magnetic fields.We find that the transmission spectrum linewidth of PHVVB can be effectively maintained regardless of the TC.Still,the width of transmission peaks increases slightly as the beam size expands in hot atomic vapor.This distinctive quantum coherence phenomenon,demonstrated by the interaction of an atomic medium with a hybrid vector-structured beam,might be anticipated to open up new opportunities for quantum coherence modulation and accurate magnetic field measurement.
基金supported by the National Natural Science Foundation of China(Grant Nos.U22A2008,and 12404484)the Sichuan Province Science and Technology Support Program(Grant No.25QNJJ2419)+1 种基金the National Key Research and Development Program of China(Grant No.2021YFB2800703)the Laoshan Laboratory Science and Technology Innovation Project(Grant No.LSKJ202200801)。
文摘Focused vector vortex beams(VVBs)offer significant potential for applications in nonlinear effects,quantum optics,and communications due to their symmetric intensity patterns,phase singularities,and structured polarization profiles.Nevertheless,the emerging frontier of dynamically tunable VVBs in the THz regime faces critical limitations in conventional static metasurface implementations,hindering their full potential for advanced photonic applications.In this work,we propose and demonstrate a design strategy,which employs dielectric cascaded metasurfaces to generate VVBs with tunable characteristics through mechanical twisting.To achieve this,LayerⅠis constructed from birefringent silicon pillars with rectangular configurations,enabling independent encoding of orthogonal circularly polarized channels via spin-decoupled phasing techniques,while LayerⅡis composed of cylindrical silicon pillars with polarization-maintaining properties to control the focal length.The generation and modulation of VVBs are achieved by mechanically adjusting the relative angles between these two layers,allowing for dynamic tuning of the beam's properties.Experimentally,we further present the accurate generation of first-and second-order focused VVBs with a high focusing efficiency(>12.9%),consistent with theoretical predictions.Moreover,the system exhibited continuous focal length tuning across 26λ-10.4λby rotating the layers from 90°to 240°,achieving a 42.8%modulation depth,while maintaining radial symmetry,as confirmed by an absolute percentage error analysis(<9.8%).The demonstrated mechanical tuning mechanism provides a practical pathway toward adaptive THz photonic devices,bridging critical gaps in real-world applications ranging from polarization-encoded communications to depthresolved biomedical imaging.
基金supported by the National Natural Science Foundation of China(No.U23A20377)the Natural Science Foundation of Henan Province(No.232300421389)。
文摘In this Letter,by exploiting the spin-to-orbital angular momentum conversion capability and the polarization selectivity characteristic of cholesteric liquid crystal planar optical elements,an approach of combing two cholesteric liquid crystal layers with opposite handedness and independent surface patterns is proposed and investigated for generating arbitrary vector vortex beams on the hybrid-order Poincarésphere.Furthermore,the intensity profiles and polarization distributions of typical vector vortex beams are experimentally demonstrated and analyzed,which shows good agreement with the theoretical prediction.The approach also suggests its advantages of operating light in the polychromatic spectral region of Bragg reflection.Our method presents a simple and direct way of phase and polarization manipulation,which also provides promising opportunities for developing advanced applications in structured light,high-resolution imaging,and information processing.
基金supported by the National Key R&D Program of China(No.2021YFC290202)the National Natural Science Foundation of China(No.51874301)the Primary Research&Development Plan of Xuzhou City(No.KC20162)。
文摘Toroidal multipole is a special current distribution that has many different characteristics from electric multipole and magnetic multipole distributions.Because of its special properties,the toroidal dipole is a research hotspot in the field of metamaterials and nanophotonics.However,the low scattering of the toroidal dipole moment makes its excitation a challenging task.At present,there are relatively few studies on its specific engineering applications.In this paper,by slotting in the rectangular cavity,the excitation of an equivalent toroidal dipole is successfully achieved over a wide frequency range of 53-58 GHz.Results indicate that under the action of the toroidal dipole,the TE_(10)mode electromagnetic waves transmitted in the rectangular waveguide are converted into vector beams and are radiated outwards.Further adjusting the spatial distribution of the magnetic dipoles in the toroidal dipoles yields results that indicate that the resonance mode in the slot is still dominated by the magnetic toroidal dipole moment,and the electromagnetic waves radiating outward are vortex beams carrying vector polarization.The scattered energy of each dipole moment inside the antenna is calculated.This calculation verifies that the mass of the vector beam and vector vortex beam is closely related to the toroidal dipole supported by this antenna.The proposed structure can be applied to explorations in vortex filtering,in photon entanglement,and in the photonic spin Hall effect.
基金supported by the Natural Science Foundation of Zhejiang Province (No.LY24A040001)the Ningbo Youth Science and Technology Innovation Leading Talent Project (No.2023QL001)+2 种基金the Villum Fonden (No.37372)the Danmarks Frie Forskningsfond (No.1134-00010B)the Fundamental Research Funds of Shaanxi Key Laboratory of Artificially Structured Functional Materials and Devices。
文摘Vector vortex beams(VVBs), novel structured optical fields that combine the polarization properties of vector beams and phase characteristics of vortex beams, have garnered widespread attention in the photonics community. Capitalizing on recently developed metasurfaces, miniaturized VVB generators with advanced properties have been implemented. However,metasurface-empowered VVB generators remain static and can only generate one pre-designed structured light. Here, we propose a kind of phase change metasurface for tunable vector beam generation by utilizing anisotropic Ge2Sb2Se4Te1(GSST) unit cells with tunable phase retardation when GSST transits between two different phase states. By properly rotating the orientations of the tunable GSST unit structures that transit between quarter-wave plates and half-wave plates, we can effectively transform incident plane waves into vector beams with distinct topological charges and polarization states.When GSST is in the amorphous state, the designed metasurface can transmit circularly polarized light into VVBs. In the crystalline state, the same GSST metasurface converts linearly polarized light into second-order radially polarized(RP) and azimuthally polarized(AP) beams. Our phase-change metasurface paves the way for precise control over the polarization patterns and vortex characteristics of beams, thereby enabling the exact manipulation of beam structures through the alteration of their phase states.
基金This project received funding from the European Union’s Horizon 2020 research and innovation program(Future and Emerging Technologies)under Grant Agreement No.828978.
文摘Scattering phenomena affect light propagation through any kind of medium from free space to biological tissues.Finding appropriate strategies to increase the robustness to scattering is the common requirement in developing both communication protocols and imaging systems.Recently,structured light has attracted attention due to its seeming scattering resistance in terms of transmissivity and spatial behavior.Moreover,correlation between optical polarization and orbital angular momentum(OAM),which characterizes the so-called vector vortex beams(VVBs)states,seems to allow for the preservation of the polarization pattern.We extend the analysis by investigating both the spatial features and the polarization structure of vectorial optical vortexes propagating in scattering media with different concentrations.Among the observed features,we find a sudden swift decrease in contrast ratio for Gaussian,OAM,and VVB modes for concentrations of the adopted scattering media exceeding 0.09%.Our analysis provides a more general and complete study on the propagation of structured light in dispersive and scattering media.
基金supported by the National High Technology Research and Development Program of China(No.2015AA016301)the National Key R&D Program of China(No.2017YFB1002900)the Jiangsu Provincial Key R&D Program(No.BE2016216)
文摘We propose theoretically and verify experimentally a compact optical configuration to directly generate arbitrary vector vortex beams on a hybrid-order Poincare sphere with good flexibility and high efficiency based on a reflective phase-only liquid crystal spatial light modulator （LC-SLM）. The conversion system, consisting of an LC-SLM and a quarter-wave plate, can be considered a flexible dielectric metasurface to simultaneously modulate inhomogeneous polarization and helical phase-front. This approach has some advantages, including a simple experimental setup, good flexibility, and high efficiency. superposition existing in the conventional method are potential applications in many advanced domains. Orthogonally polarized modes alignment and an explicit not necessary in the proposed method, which exhibits
基金National Natural Science Foundation of China(NSFC)(11274106,11474089)
文摘We propose theoretically and verify experimentally a method of combining a q-plate and a spiral phase plate to generate arbitrary vector vortex beams on a hybrid-order Poincaré sphere. We demonstrate that a vector vortex beam can be decomposed into a vector beam and a vortex, whereby the generation can be realized by sequentially using a q-plate and a spiral phase plate. The generated vector beam, vortex, and vector vortex beam are verified and show good agreement with the prediction. Another advantage that should be pointed out is that the spiral phase plate and q-plate are both fabricated on silica substrates, suggesting the potential possibility to integrate the two structures on a single plate. Based on a compact method of transmissive-type transformation, our scheme may have potential applications in future integrated optical devices.
文摘The performance breakthroughs of some stealth materials have benefited from incorporating biomimetic concepts,and the design ideas of wave-absorbing metamaterials have been greatly broadened.How-ever,stealth materials developed based on a single biological structure still have limitations regarding overall performance and design freedom.Herein,a dual-structure element combination model with a butterfly-wing porous structure and moth-eye raised structure arranged in an orderly manner is estab-lished.Carbonyl iron and polyurethane are mixed as wave absorbents,and the model is utilized to make a biomimetic metamaterial(CSMA),which has an absorption rate of more than 90%at 6.07-18 GHz,achieving broadband effective absorption.It has been verified that the two biostructures designed after an ordered arrangement show synergistic effects in the combined model,and the cooperation between the structures induces the formation of current vector vortices,which are able to induce microwave losses to broaden the effective absorbing bandwidth.Further,the model has the combined application performance of polarization insensitivity,strong stability of oblique incidence,and low bistatic RCS.Such a thought based on the combination of multiple components provides an effective strategy for the design of broadband-absorbing metamaterials.
基金the Chinese Scholarship Council is acknowledged.This work was supported by the UK’s Engineering and Physical Sciences Research Council(Grant Nos.EP/V000624/1,EP/X03495X/1,EP/X041166/1,and EP/T02643X/1)the Royal Society(Grant No.RG\R2\232531).
文摘The unique phase profile and polarization distribution of the vector vortex beam(VVB)have been a subject of increasing interest in classical and quantum optics.The development of higher-order Poincarésphere(HOPS)and hybrid-order Poincarésphere(HyOPS)has provided a systematic description of VVB.However,the generation of arbitrary VVBs on a HOPS and a HyOPS via a metasurface lacks a unified design framework,despite numerous reported approaches.We present a unified design framework incorporating all design parameters(e.g.,focal lengths and orders)of arbitrary HOPS and HyOPS beams into a single equation.In proof-of-concept experiments,we experimentally demonstrated four metasurfaces to generate arbitrary beams on the fifth-order HOPS(nonfocused and tightly focused,NA 0.89),0-2 order,and 0-1 order HyOPS.We showed HOPS beams’propagation and focusing properties,the superresolution focusing characteristics of the first-order cylindrical VVBs,and the different focusing properties of integerorder and fractional-order cylindrical VVBs.The simplicity and feasibility of the proposed design framework make it a potential catalyst for arbitrary VVBs using metasurfaces in applications of optical imaging,communication,and optical trapping.
基金National Key Research and Development Program of China(2022YFA1404800,2019YFA0705000)National Natural Science Foundation of China(12174280,12204340,12192254,92250304,12434012)+3 种基金China Postdoctoral Science Foundation(2022M722325)Priority Academic Program Development of Jiangsu Higher Education InstitutionsJiangsu Funding Program for Excellent Postdoctoral Talent(2022ZB593)Key Lab of Modern Optical Technologies of Jiangsu Province(KJS2138)。
文摘The rotational Doppler effect holds significant potential for remote sensing of rotating objects due to its real-time performance and non-contact advantages.A single-ring beam is used to measure rotation speed.To enhance the signal-to-noise ratio and measure additional parameters,multiple rings are introduced in the context of a rotational Doppler effect.However,the interference between these rings poses a challenge for multitasking detection applications.In this study,cross-polarization superposition was applied to generate an ultra-dense vector perfect vortex beam that exhibited sensitivity to spatial position and object size,and flexibility in designing topological charge combinations for generating frequency combs.A proof-of-principle experiment was conducted to demonstrate its capability in improving the signal-to-noise ratio,and accurately perceiving both the radius of rotation and radial size.An ultra-dense vector perfect vortex beam provides a general strategy for beam construction and the multi-parameter perception of rotating objects,thereby enabling potential applications in the measurement of velocity gradient measurement of fluids.
