Optical three-dimensional(3D)measurement is a critical tool in micro-nano manufacturing,the automotive industry,and medical technology due to its nondestructive nature,high precision,and sensitivity.However,passive li...Optical three-dimensional(3D)measurement is a critical tool in micro-nano manufacturing,the automotive industry,and medical technology due to its nondestructive nature,high precision,and sensitivity.However,passive light field system still requires a refractive primary lens to collect light of the scene,and structured light can not work well with the highly refractive object.Meta-optics,known for being lightweight,compact,and easily integrable,has enabled advancements in passive metalens-array light fields and active structured light techniques.Here,we propose and experimentally validate a novel 3D measurement metasystem.It features a transmitting metasurface generating chromatic line focuses as depth markers and a symmetrically arranged receiving metasurface collecting depth-dependent spectral responses.A lightweight,physically interpretable algorithm processes these data to yield high-precision depth information efficiently.Experiments on metallic and wafer materials demonstrate a depth accuracy of±20μm and lateral accuracy of±10μm.This single-layer optical metasystem,characterized by simplicity,micro-level accuracy,easy installation and scalability,shows potential for diverse applications,including process control,surface morphology analysis,and production measurement.展开更多
At present,the traditional channel estimation algorithms have the disadvantages of over-reliance on initial conditions and high complexity.The bacterial foraging optimization(BFO)-based algorithm has been applied in w...At present,the traditional channel estimation algorithms have the disadvantages of over-reliance on initial conditions and high complexity.The bacterial foraging optimization(BFO)-based algorithm has been applied in wireless communication and signal processing because of its simple operation and strong self-organization ability.But the BFO-based algorithm is easy to fall into local optimum.Therefore,this paper proposes the quantum bacterial foraging optimization(QBFO)-binary orthogonal matching pursuit(BOMP)channel estimation algorithm to the problem of local optimization.Firstly,the binary matrix is constructed according to whether atoms are selected or not.And the support set of the sparse signal is recovered according to the BOMP-based algorithm.Then,the QBFO-based algorithm is used to obtain the estimated channel matrix.The optimization function of the least squares method is taken as the fitness function.Based on the communication between the quantum bacteria and the fitness function value,chemotaxis,reproduction and dispersion operations are carried out to update the bacteria position.Simulation results showthat compared with other algorithms,the estimationmechanism based onQBFOBOMP algorithm can effectively improve the channel estimation performance of millimeter wave(mmWave)massive multiple input multiple output(MIMO)systems.Meanwhile,the analysis of the time ratio shows that the quantization of the bacteria does not significantly increase the complexity.展开更多
Planar metasurfaces with both chirality and high quality(Q)factors have important applications in many fields.A chiral metasurface empowered by a bound state in the continuum(BIC)can provide a perfect solution to this...Planar metasurfaces with both chirality and high quality(Q)factors have important applications in many fields.A chiral metasurface empowered by a bound state in the continuum(BIC)can provide a perfect solution to this problem.However,the metasurface design method based on physical intuition requires a substantial amount of computational resources,and the limited design parameters of meta-atoms restrict metasurfaces from achieving optimal optical performance.Here,we apply an inverse design method based on adjoint topological optimization to automatically alter the refractive index distribution of the metasurface,thereby maximizing the chirality of the BIC metasurface.Through this inverse design approach,chiral BIC metasurfaces with 3D intrinsic chirality at the target wavelength are designed and fabricated.To demonstrate the versatility of the proposed inverse design method,the metasurfaces with specific elliptic polarization states are designed.The inverse design method we propose provides an effective solution for the efficient design of chiral BIC metasurfaces.展开更多
Light detection and ranging(LiDAR)is widely used for active three-dimensional(3D)perception.Beam scanning LiDAR provides high accuracy and long detection range with limited detection efficiency,while flash LiDAR can a...Light detection and ranging(LiDAR)is widely used for active three-dimensional(3D)perception.Beam scanning LiDAR provides high accuracy and long detection range with limited detection efficiency,while flash LiDAR can achieve high-efficiency detection through the snapshot approach at the expense of reduced accuracy and range.With the synergy of these distinct detection approaches,we develop a miniaturized dual-mode,reconfigurable beam forming device by cascading Pancharatnam-Berry phase and propagation phase metasurfaces,integrated with a microactuator.By modulating incident light polarization,we can switch the output beam of the device between the beam array scanning mode and flash illuminating mode.In the scanning mode,the device demonstrates a continuously tunable angular resolution and a±35°field of view(FoV)through driving the micro-actuator to achieve the lateral translation of±100μm.In the flash mode,uniform illumination across the entire FoV is achieved.As a proof of concept,we propose an adaptive 3D reconstruction scheme that leverages the device’s capability to switch operation modes and adjust detection resolution.Together,the proposed device and the detection scheme constitute a dualmode LiDAR system,demonstrating high adaptability to diverse environments and catalyze the applications of more efficient and compact 3D detection systems.展开更多
Point-cloud-projection-based stereo vision technology is widely applied in 3D reconstruction, robotic vision, and virtual reality. A metasurface, known for its exceptional light-field manipulation capabilities and com...Point-cloud-projection-based stereo vision technology is widely applied in 3D reconstruction, robotic vision, and virtual reality. A metasurface, known for its exceptional light-field manipulation capabilities and compact integration, offers a promising approach to reducing system size while enhancing functionality. In this work, we propose and implement a short-wave infrared 3D structured light detection system based on a metasurface supporting a bound state in the continuum(BIC). The designed BIC metasurface exhibits wavelength selectivity, generating a point cloud projection array exclusively under 1350 nm laser illumination, effectively minimizing interference from environmental light and enabling penetration through certain packaging materials opaque to visible light. Using this system, we successfully demonstrate 3D detection and reconstruction of concealed objects, such as lenses and workpieces, within opaque packaging. Our design provides a non-contact,penetrating 3D reconstruction approach for industrial inspection, offering potential applications in nondestructive quality control.展开更多
A fast and effective shape reconstruction method of large aspheric specular surfaces with high order terms is proposed in fringe reflection technique, which combines modal estimation with high-order finite- difference...A fast and effective shape reconstruction method of large aspheric specular surfaces with high order terms is proposed in fringe reflection technique, which combines modal estimation with high-order finite- difference algorithm. The iterative equation with high- order truncation errors is derived for calculating the specular surface with large aperture based on high-order finite-difference algorithm. To achieve the wavefront estimation and improve convergence speed, the numerical orthogonal transformation method based on Zemike polynomials is implemented to obtain the initial iteration value. The reconstruction results of simulated surface identified the advantages of the proposed method. Furthermore, a freeform in illuminating system has been used to demonstrate the validity of the improved method in practical measurement. The results show that the proposed method has the advantages of making the reconstruction of different shape apertures accurate and rapid. In general, this method performs well in measuring large complex objects with high frequency information in practical measurement.展开更多
基金financial supports from the National Key R&D Program of China (2021YFA1401200)Beijing Outstanding Young Scientist Program (BJJWZYJH01201910007022)+1 种基金National Natural Science Foundation of China (No. U21A20140, No. 92050117, No. 62105024) programBeijing Natural Science Foundation (JQ24028)
文摘Optical three-dimensional(3D)measurement is a critical tool in micro-nano manufacturing,the automotive industry,and medical technology due to its nondestructive nature,high precision,and sensitivity.However,passive light field system still requires a refractive primary lens to collect light of the scene,and structured light can not work well with the highly refractive object.Meta-optics,known for being lightweight,compact,and easily integrable,has enabled advancements in passive metalens-array light fields and active structured light techniques.Here,we propose and experimentally validate a novel 3D measurement metasystem.It features a transmitting metasurface generating chromatic line focuses as depth markers and a symmetrically arranged receiving metasurface collecting depth-dependent spectral responses.A lightweight,physically interpretable algorithm processes these data to yield high-precision depth information efficiently.Experiments on metallic and wafer materials demonstrate a depth accuracy of±20μm and lateral accuracy of±10μm.This single-layer optical metasystem,characterized by simplicity,micro-level accuracy,easy installation and scalability,shows potential for diverse applications,including process control,surface morphology analysis,and production measurement.
基金supported by the National Natural Science Foundation of China(Nos.61861015,62061013 and 61961013)Key Research and Development Program of Hainan Province(No.ZDYF2019011)+3 种基金National Key Research and Development Program of China(No.2019CXTD400)Young Elite Scientists Sponsorship Program by CAST(No.2018QNRC001)Scientific Research Setup Fund of Hainan University(No.KYQD(ZR)1731)the Natural Science Foundation High-Level Talent Project of Hainan Province(No.622RC619).
文摘At present,the traditional channel estimation algorithms have the disadvantages of over-reliance on initial conditions and high complexity.The bacterial foraging optimization(BFO)-based algorithm has been applied in wireless communication and signal processing because of its simple operation and strong self-organization ability.But the BFO-based algorithm is easy to fall into local optimum.Therefore,this paper proposes the quantum bacterial foraging optimization(QBFO)-binary orthogonal matching pursuit(BOMP)channel estimation algorithm to the problem of local optimization.Firstly,the binary matrix is constructed according to whether atoms are selected or not.And the support set of the sparse signal is recovered according to the BOMP-based algorithm.Then,the QBFO-based algorithm is used to obtain the estimated channel matrix.The optimization function of the least squares method is taken as the fitness function.Based on the communication between the quantum bacteria and the fitness function value,chemotaxis,reproduction and dispersion operations are carried out to update the bacteria position.Simulation results showthat compared with other algorithms,the estimationmechanism based onQBFOBOMP algorithm can effectively improve the channel estimation performance of millimeter wave(mmWave)massive multiple input multiple output(MIMO)systems.Meanwhile,the analysis of the time ratio shows that the quantization of the bacteria does not significantly increase the complexity.
基金National Key Research and Development Program of China(2022YFB4600204)National Natural Science Foundation of China(12104046,62105024,61775019,U21A20140)。
文摘Planar metasurfaces with both chirality and high quality(Q)factors have important applications in many fields.A chiral metasurface empowered by a bound state in the continuum(BIC)can provide a perfect solution to this problem.However,the metasurface design method based on physical intuition requires a substantial amount of computational resources,and the limited design parameters of meta-atoms restrict metasurfaces from achieving optimal optical performance.Here,we apply an inverse design method based on adjoint topological optimization to automatically alter the refractive index distribution of the metasurface,thereby maximizing the chirality of the BIC metasurface.Through this inverse design approach,chiral BIC metasurfaces with 3D intrinsic chirality at the target wavelength are designed and fabricated.To demonstrate the versatility of the proposed inverse design method,the metasurfaces with specific elliptic polarization states are designed.The inverse design method we propose provides an effective solution for the efficient design of chiral BIC metasurfaces.
基金supported by National Natural Science Foundation of China(Grant No.U21A6003)National Key Research and Development Program of China(Grant No.2023YFB3906300)+1 种基金support from the Beijing Outstanding Young Scientist Program(Grant No.JWZQ20240101028)support from National Natural Science Foundation of China(Grant No.62475018).
文摘Light detection and ranging(LiDAR)is widely used for active three-dimensional(3D)perception.Beam scanning LiDAR provides high accuracy and long detection range with limited detection efficiency,while flash LiDAR can achieve high-efficiency detection through the snapshot approach at the expense of reduced accuracy and range.With the synergy of these distinct detection approaches,we develop a miniaturized dual-mode,reconfigurable beam forming device by cascading Pancharatnam-Berry phase and propagation phase metasurfaces,integrated with a microactuator.By modulating incident light polarization,we can switch the output beam of the device between the beam array scanning mode and flash illuminating mode.In the scanning mode,the device demonstrates a continuously tunable angular resolution and a±35°field of view(FoV)through driving the micro-actuator to achieve the lateral translation of±100μm.In the flash mode,uniform illumination across the entire FoV is achieved.As a proof of concept,we propose an adaptive 3D reconstruction scheme that leverages the device’s capability to switch operation modes and adjust detection resolution.Together,the proposed device and the detection scheme constitute a dualmode LiDAR system,demonstrating high adaptability to diverse environments and catalyze the applications of more efficient and compact 3D detection systems.
基金National Key Researchand Development Program of China(2022YFB4600204)Beijing Outstanding Young Scientist Program(BJJWZYJH01201910007022)+1 种基金National Natural Science Foundation of China(12104046,62105024,61775019,62475018,U21A20140)Natural Science Foundation of Beijing Municipality(JQ24028).
文摘Point-cloud-projection-based stereo vision technology is widely applied in 3D reconstruction, robotic vision, and virtual reality. A metasurface, known for its exceptional light-field manipulation capabilities and compact integration, offers a promising approach to reducing system size while enhancing functionality. In this work, we propose and implement a short-wave infrared 3D structured light detection system based on a metasurface supporting a bound state in the continuum(BIC). The designed BIC metasurface exhibits wavelength selectivity, generating a point cloud projection array exclusively under 1350 nm laser illumination, effectively minimizing interference from environmental light and enabling penetration through certain packaging materials opaque to visible light. Using this system, we successfully demonstrate 3D detection and reconstruction of concealed objects, such as lenses and workpieces, within opaque packaging. Our design provides a non-contact,penetrating 3D reconstruction approach for industrial inspection, offering potential applications in nondestructive quality control.
文摘A fast and effective shape reconstruction method of large aspheric specular surfaces with high order terms is proposed in fringe reflection technique, which combines modal estimation with high-order finite- difference algorithm. The iterative equation with high- order truncation errors is derived for calculating the specular surface with large aperture based on high-order finite-difference algorithm. To achieve the wavefront estimation and improve convergence speed, the numerical orthogonal transformation method based on Zemike polynomials is implemented to obtain the initial iteration value. The reconstruction results of simulated surface identified the advantages of the proposed method. Furthermore, a freeform in illuminating system has been used to demonstrate the validity of the improved method in practical measurement. The results show that the proposed method has the advantages of making the reconstruction of different shape apertures accurate and rapid. In general, this method performs well in measuring large complex objects with high frequency information in practical measurement.
