Metalenses have gained significant attention and have been widely utilized in optical systems for focusing and imaging,owing to their lightweight,high-integration,and exceptional-flexibility capabilities.Traditional d...Metalenses have gained significant attention and have been widely utilized in optical systems for focusing and imaging,owing to their lightweight,high-integration,and exceptional-flexibility capabilities.Traditional design methods neglect the coupling effect between adjacent meta-atoms,thus harming the practical performance of meta-devices.The existing physical/data-driven optimization algorithms can solve the above problems,but bring significant time costs or require a large number of data-sets.Here,we propose a physics-data-driven method employing an“intelligent optimizer”that enables us to adaptively modify the sizes of the meta-atom according to the sizes of its surrounding ones.The implementation of such a scheme effectively mitigates the undesired impact of local lattice coupling,and the proposed network model works well on thousands of data-sets with a validation loss of 3×10^(−3).Based on the“intelligent optimizer”,a 1-cm-diameter metalens is designed within 3 hours,and the experimental results show that the 1-mm-diameter metalens has a relative focusing efficiency of 93.4%(compared to the ideal focusing efficiency)and a Strehl ratio of 0.94.Compared to previous inverse design method,our method significantly boosts designing efficiency with five orders of magnitude reduction in time.More generally,it may set a new paradigm for devising large-aperture meta-devices.展开更多
Super-resolution(SR)microscopy has dramatically enhanced our understanding of biological processes.However,scattering media in thick specimens severely limits the spatial resolution,often rendering the images unclear ...Super-resolution(SR)microscopy has dramatically enhanced our understanding of biological processes.However,scattering media in thick specimens severely limits the spatial resolution,often rendering the images unclear or indistinguishable.Additionally,live-cell imaging faces challenges in achieving high temporal resolution for fast-moving subcellular structures.Here,we present the principles of a synthetic wave microscopy(SWM)to extract three-dimensional information from thick unlabeled specimens,where photobleaching and phototoxicity are avoided.SWM exploits multiple-wave interferometry to reveal the specimen’s phase information in the area of interest,which is not affected by the scattering media in the optical path.SWM achieves~0.42λ/NA resolution at an imaging speed of up to 106 pixels/s.SWM proves better temporal resolution and sensitivity than the most conventional microscopes currently available while maintaining exceptional SR and anti-scattering capabilities.Penetrating through the scattering media is challenging for conventional imaging techniques.Remarkably,SWM retains its efficacy even in conditions of low signal-to-noise ratios.It facilitates the visualization of dynamic subcellular structures in live cells,encompassing tubular endoplasmic reticulum(ER),lipid droplets,mitochondria,and lysosomes.展开更多
Dielectric metasurfaces are crucial for enhancing optical nonlinear generation,particularly membrane metasurfaces with multipolar resonances and compact size.Investigating silicon dimer-hole membrane metasurfaces,Rahm...Dielectric metasurfaces are crucial for enhancing optical nonlinear generation,particularly membrane metasurfaces with multipolar resonances and compact size.Investigating silicon dimer-hole membrane metasurfaces,Rahmani,and Xu show how bound states in the continuum(BICs)can be formed and transformed into quasi-BICs by adjusting hole gaps.This innovation enables efficient conversion of infrared images to visible range,promising applications in nonlinear photonics and near-infrared imaging technologies.展开更多
Imaging polarimetry is one of the most widely used analytical technologies for object detection and analysis.To date,most metasurface-based polarimetry techniques are severely limited by narrow operating bandwidths an...Imaging polarimetry is one of the most widely used analytical technologies for object detection and analysis.To date,most metasurface-based polarimetry techniques are severely limited by narrow operating bandwidths and inevitable crosstalk,leading to detrimental effects on imaging quality and measurement accuracy.Here,we propose a crosstalkfree broadband achromatic full Stokes imaging polarimeter consisting of polarization-sensitive dielectric metalenses,implemented by the principle of polarization-dependent phase optimization.Compared with the single-polarization optimization method,the average crosstalk has been reduced over three times under incident light with arbitrary polarization ranging from 9μm to 12μm,which guarantees the measurement of the polarization state more precisely.The experimental results indicate that the designed polarization-sensitive metalenses can effectively eliminate the chromatic aberration with polarization selectivity and negligible crosstalk.The measured average relative errors are 7.08%,8.62%,7.15%,and 7.59%at 9.3,9.6,10.3,and 10.6μm,respectively.Simultaneously,the broadband full polarization imaging capability of the device is also verified.This work is expected to have potential applications in wavefront detection,remote sensing,light-field imaging,and so forth.展开更多
Optical camouflage is a magical capability of animals as first noticed in 1794 by Erasmus Darwin in Zoonomia,but current biomimetic camouflage strategies cannot be readily applied in complex environments involving mul...Optical camouflage is a magical capability of animals as first noticed in 1794 by Erasmus Darwin in Zoonomia,but current biomimetic camouflage strategies cannot be readily applied in complex environments involving multispectral and in particular multi-polarization detection.Here we develop a plasmonic approach toward broadband infrared polarimetric crypsis,where the polarized thermal emission near the pseudo-Brewster angle is the main signal source and no existing polarizing camouflage technique has been discovered in nature.Based on all-metallic subwavelength structures,an electrodynamic resistance-reduction mechanism is proposed to avoid the significant polarization-dependent infrared absorption/radiation.It is also found that the structured metal surface presents giant extrinsic anisotropy regarding the phase shift between orthogonal polarization states,which helps to realize ultrahigh-efficiency and tunable polarization conversion in an unprecedented manner.Finally,we note that the catenary optical theory may provide a useful means to explain and predict these unusual performances.展开更多
Spin-orbit optical phenomena pertain to the wider class of electromagnetic effects originating from the interaction of the photon spin with the spatial structure and propagation characteristics of an optical wave,medi...Spin-orbit optical phenomena pertain to the wider class of electromagnetic effects originating from the interaction of the photon spin with the spatial structure and propagation characteristics of an optical wave,mediated by suitable optical media.There are many emerging photonic applications of spin-orbit interactions(SOI)of light,such as control of the optical wave propagation via the spin,enhanced optical manipulation,and generation of structured optical fields.Unfortunately,current applications are based on symmetric SOI,that is,the behaviours of polarized photons with two opposite spins are opposite,leading to the limit of spin-based multiplexers.The symmetry of SOI can be broken in our proposed metasurfaces,consisting of spatially varying birefringence,which can arbitrarily and independently build SOI for two opposite spins without reduction of optical energy usage.We obtain three kinds of dual-functional metasurfaces at visible and infrared wavelengths with high efficiency.Our concept of generation of asymmetric SOI for two spins,using anisotropic metasurfaces,will open new degrees of freedoms for building new types of spin-controlled multifunctional shared-aperture devices for the generation of complex structured optical fields.展开更多
Dispersion control is crucial in optical systems,and chromatic aberration is an important factor affecting imaging quality in imaging systems.Due to the inherent property of materials,dispersion engineering is complex...Dispersion control is crucial in optical systems,and chromatic aberration is an important factor affecting imaging quality in imaging systems.Due to the inherent property of materials,dispersion engineering is complex and needs to trade off other aberration in traditional ways.Although metasurface offers an effective method to overcome these limits and results in well-engineered dispersion,off-axis dispersion control is still a challenging topic.In this paper,we design a single-layer metalens which is capable of focusing at three wavelengths(473 nm,532 nm,and 632 nm)with different incident angles(0°,-17°and 17°)into the same point.We also demonstrate that this metalens can provide an alternative for the bulky color synthetic prism in a 3-chips digital micromirror device(DMD)laser projection system.Through this approach,various off-axis dispersion controlling optical devices could be realized.展开更多
1.Introduction Artificial intelligence(AI)is committed to the realization of machine-borne intelligence.The technologies underpinning AI have made huge leaps in the past decade,bringing exciting applications such as l...1.Introduction Artificial intelligence(AI)is committed to the realization of machine-borne intelligence.The technologies underpinning AI have made huge leaps in the past decade,bringing exciting applications such as language understanding,vision recognition,and intelligent digital assistants.However,contemporary AI systems are good at specific predefined tasks and are unable to learn by themselves from data or from experience,intuitive reasoning,and adaptation.展开更多
In this paper,we demonstrate an auto accurate alignment method to align mask-substrate in the prototype of plasmonic lithography(PL),which is essential for multilayer nanostructure fabrication with high resolution,low...In this paper,we demonstrate an auto accurate alignment method to align mask-substrate in the prototype of plasmonic lithography(PL),which is essential for multilayer nanostructure fabrication with high resolution,low cost,high efficiency,and high throughput,such as circuit manufacturing and other applications.We obtained an alignment signal with sensitivity better than 20 nm by using the Moiréfringe image.However,only using the Moiréfringes cannot guarantee the alignment of the mask and the substrate because the Moiréfringe repeats itself when the mask and substrate are offset by a fixed displacement.To eliminate the ambiguity,boxes and the crosses alignment marks are designed beside the grating marks on the substrate and the mask,respectively.A two-step alignment scheme including coarse alignment and fine alignment is explored in the auto alignment system.In the stage of coarse alignment,the edge detection algorithm based on Canny operator is adopted to detect the edges image effectively.In the process of fine alignment,Fourier transform based on Moiréfringe image is obtained to improve the alignment accuracy.In addition,experimental results of overlay indicate that PL can obtain sub-100 nm alignment accuracy over an area of 1 cm^2 using the proposed two-step alignment scheme.Via the substrate-mask mismatch compensation,better stages and precise environment control,it is expected that much higher overlay accuracy is feasible.展开更多
The current metadata modeling techniques can not meet the needs of knowledge conception expression, knowledge organization, and metadata semantic consistency in geological domain. This paper introduces ontology and in...The current metadata modeling techniques can not meet the needs of knowledge conception expression, knowledge organization, and metadata semantic consistency in geological domain. This paper introduces ontology and integrates this theory to geological domain metadata modeling. It adopts the first order logic equivalent algorithm and defines the metadata extended model as a quaternion group which is consists of geological term set, geological term definition set, attribute definition set and instance set. It also provides the formal description of each set. Finally the five steps for building geological domain metadata extended model are given. The result presents that this model not only provides the content standards for geological domain knowledge representation and knowledge organization, but also provides the basis for geological domain multi-source data and historical data integration and application in semantic consistency.展开更多
Optics is an ancient and vibrant subject with a rich his-tory of thousands of years.Since Maxwell discovered that light is an electromagnetic wave,optics has always been accompanied by electricity.Optics and opto-elec...Optics is an ancient and vibrant subject with a rich his-tory of thousands of years.Since Maxwell discovered that light is an electromagnetic wave,optics has always been accompanied by electricity.Optics and opto-electronics play a vital role in many key fields related to the devel-opment and progress of mankind,such as energy,infor-mation,internet,astronomy,and medicine,etc.Many large-scale scientific projects,ranging from laser nuclear fusion to gravitational wave detection,from large-aperture telescopes to lithography equipment,are mainly based on opto-electronic science.展开更多
Independent manipulation of transmitted and reflected light fields is a key technology for the realization of multifunctional optical applications,which can be implemented based on multilayered plasmonic or supercell ...Independent manipulation of transmitted and reflected light fields is a key technology for the realization of multifunctional optical applications,which can be implemented based on multilayered plasmonic or supercell subwavelength structures.However,the former is not suitable for the optical bands,while the latter is insufficient in generating large phase gradients.Here,an adjoint-optimization-based inverse design methodology is proposed,which utilizes the polarization-selective local interference between individual meta-atoms and enables monolayer dielectric metasurfaces to decouple the wavefront of transmitted and reflected optical fields.Moreover,this methodology serves to mitigate the aperiodic electromagnetic crosstalk inherent between adjacent meta-atoms,consequently leading to a significant enhancement in the performance of meta-devices.We analyzed the physical mechanism of adjoint optimization and proposed the concept of phase factors,highlighting their importance in the rapid inverse design of meta-devices—an aspect often overlooked in previous research.To demonstrate the feasibility and robustness of our method,we optimize monolayer metasurfaces with different initial structures.These devices efficiently focus and deflect x-linearly and y-linearly polarized incident light in transmission and reflection spaces,respectively.Overall,this methodology holds immense potential for designing multifunctional,high-performing metasurfaces that meet multiple constraints,opening up broad prospects for applications.展开更多
Multi-dimensional optical imaging systems that simultaneously gather intensity,depth,polarimetric,and spectral information have numerous applications in medical sciences,robotics,and surveillance.Nevertheless,most cur...Multi-dimensional optical imaging systems that simultaneously gather intensity,depth,polarimetric,and spectral information have numerous applications in medical sciences,robotics,and surveillance.Nevertheless,most current approaches require mechanical moving parts or multiple modulation processes and thus suffer from long acquisition time,high system complexity,or low sampling resolution.Here,a methodology to build snapshot multi-dimensional lensless imaging is proposed by combining planar-optics and computational technology,benefiting from sufficient flexibilities in optical engineering and robust information reconstructions.Specifically,a liquid crystal diffuser based on geometric phase modulation is designed to simultaneously encode the spatial,spectral,and polarization information of an object into a snapshot detected speckle pattern.At the same time,a post-processing algorithm acts as a special decoder to recover the hidden information in the speckle with the independent and unique point spread function related to the position,wavelength,and chirality.With the merits of snapshot acquisition,multi-dimensional perception ability,simple optical configuration,and compact device size,our approach can find broad potential applications in object recognition and classification.展开更多
Optical chaotic signals emitted from an external-cavity feedback or injected laser diode enable small-signal information concealment in a noise-like carrier for secure optical communications.Due to the chaotic bandwid...Optical chaotic signals emitted from an external-cavity feedback or injected laser diode enable small-signal information concealment in a noise-like carrier for secure optical communications.Due to the chaotic bandwidth limitation resulting from intrinsic relaxation oscillation frequency of lasers,multiplexing of optical chaotic signal,such as wavelength division multiplexing in fiber,is a typical candidate for high-capacity secure applications.However,to our best knowledge,the utilization of the spatial dimension of optical chaos for free-space secure communication has not yet been reported.Here,we experimentally demonstrate a free-space all-optical chaotic communication system that simultaneously enhances transmission capacity and security by orbital angular momentum(OAM)multiplexing.Optical chaotic signals with two different OAM modes totally carrying 20 Gbps on-off keying signals are secretly transmitted over a 2 m free-space link,where the channel crosstalk of OAM modes is less than-20 d B,with the mode spacing no less than 3.The receiver can extract valid information only when capturing approximately 92.5% of the OAM beam and correctly demodulating the corresponding mode.Bit error rate below the 7%hard-decision forward error correction threshold of 3.8×10^(-3)can be achieved for the intended recipient.Moreover,a simulated weak turbulence is introduced to comprehensively analyze the influence on the system performance,including channel crosstalk,chaotic synchronization,and transmission performance.Our work may inspire structured light application in optical chaos and pave a new way for developing future high-capacity free-space chaotic secure communication systems.展开更多
The 4 m diameter SiC aspheric mirror emerges due to a series of technological breakthroughs in blank mirror preparation,asphere fabrication,and testing,as well as cladding and coating,laying the groundwork for future ...The 4 m diameter SiC aspheric mirror emerges due to a series of technological breakthroughs in blank mirror preparation,asphere fabrication,and testing,as well as cladding and coating,laying the groundwork for future research into large SiC mirrors for astronomical observation.展开更多
Wide-angle imaging and spectral detection play vital roles in tasks such as target tracking,object classification,and anti-camouflage.However,limited by their intrinsically different architectures,as determined by fre...Wide-angle imaging and spectral detection play vital roles in tasks such as target tracking,object classification,and anti-camouflage.However,limited by their intrinsically different architectures,as determined by frequency dispersion requirements,their simultaneous implementation in a shared-aperture system is difficult.Here,we propose a novel concept to realize reconfigurable dual-mode detection based on electrical-control tunable metasurfaces.As a proof-of-concept demonstration,the simultaneous implementation of wide-angle imaging and polarization-spectral detection in a miniature sharedaperture meta-optical system is realized for the first time via the electrical control of cascaded catenary-like metasurfaces.The proposed system supports the imaging(spectral)resolution of approximately 27.8 line-pairs per millimeter(lp·mm^(-1);~80 nm)for an imaging(spectral)mode from 8 to 14 μm.This system also bears a large field of view of about 70°,enabling multi-target recognition in both modes.This work may promote the miniaturization of multifunctional optical systems,including spectrometers and polarization imagers,and illustrates the potential industrial applications of meta-optics in biomedicine,security,space exploration,and more.展开更多
基金supported by the National Key Research and Development Program (2021YFA1401000)the National Natural Science Foundation of China (No.61975210,62175242 and 62305345)Sichuan Science and Technology Program (2020YFJ0001).
文摘Metalenses have gained significant attention and have been widely utilized in optical systems for focusing and imaging,owing to their lightweight,high-integration,and exceptional-flexibility capabilities.Traditional design methods neglect the coupling effect between adjacent meta-atoms,thus harming the practical performance of meta-devices.The existing physical/data-driven optimization algorithms can solve the above problems,but bring significant time costs or require a large number of data-sets.Here,we propose a physics-data-driven method employing an“intelligent optimizer”that enables us to adaptively modify the sizes of the meta-atom according to the sizes of its surrounding ones.The implementation of such a scheme effectively mitigates the undesired impact of local lattice coupling,and the proposed network model works well on thousands of data-sets with a validation loss of 3×10^(−3).Based on the“intelligent optimizer”,a 1-cm-diameter metalens is designed within 3 hours,and the experimental results show that the 1-mm-diameter metalens has a relative focusing efficiency of 93.4%(compared to the ideal focusing efficiency)and a Strehl ratio of 0.94.Compared to previous inverse design method,our method significantly boosts designing efficiency with five orders of magnitude reduction in time.More generally,it may set a new paradigm for devising large-aperture meta-devices.
基金support from CAS West Light Grant (xbzgzdsys-202206)National Key Research and Development Program of China (2021YFA1401003).
文摘Super-resolution(SR)microscopy has dramatically enhanced our understanding of biological processes.However,scattering media in thick specimens severely limits the spatial resolution,often rendering the images unclear or indistinguishable.Additionally,live-cell imaging faces challenges in achieving high temporal resolution for fast-moving subcellular structures.Here,we present the principles of a synthetic wave microscopy(SWM)to extract three-dimensional information from thick unlabeled specimens,where photobleaching and phototoxicity are avoided.SWM exploits multiple-wave interferometry to reveal the specimen’s phase information in the area of interest,which is not affected by the scattering media in the optical path.SWM achieves~0.42λ/NA resolution at an imaging speed of up to 106 pixels/s.SWM proves better temporal resolution and sensitivity than the most conventional microscopes currently available while maintaining exceptional SR and anti-scattering capabilities.Penetrating through the scattering media is challenging for conventional imaging techniques.Remarkably,SWM retains its efficacy even in conditions of low signal-to-noise ratios.It facilitates the visualization of dynamic subcellular structures in live cells,encompassing tubular endoplasmic reticulum(ER),lipid droplets,mitochondria,and lysosomes.
基金supports from Chinese Academy of Science Project xbzg-zdsys-202206.
文摘Dielectric metasurfaces are crucial for enhancing optical nonlinear generation,particularly membrane metasurfaces with multipolar resonances and compact size.Investigating silicon dimer-hole membrane metasurfaces,Rahmani,and Xu show how bound states in the continuum(BICs)can be formed and transformed into quasi-BICs by adjusting hole gaps.This innovation enables efficient conversion of infrared images to visible range,promising applications in nonlinear photonics and near-infrared imaging technologies.
基金Sichuan Science and Technology Program(2020YFJ0001)the National Natural Science Foundation of China(61975210,62222513)+1 种基金National Key Research and Development Program(SQ2021YFA1400121)China Postdoctoral Science Foundation(2021T140670)
文摘Imaging polarimetry is one of the most widely used analytical technologies for object detection and analysis.To date,most metasurface-based polarimetry techniques are severely limited by narrow operating bandwidths and inevitable crosstalk,leading to detrimental effects on imaging quality and measurement accuracy.Here,we propose a crosstalkfree broadband achromatic full Stokes imaging polarimeter consisting of polarization-sensitive dielectric metalenses,implemented by the principle of polarization-dependent phase optimization.Compared with the single-polarization optimization method,the average crosstalk has been reduced over three times under incident light with arbitrary polarization ranging from 9μm to 12μm,which guarantees the measurement of the polarization state more precisely.The experimental results indicate that the designed polarization-sensitive metalenses can effectively eliminate the chromatic aberration with polarization selectivity and negligible crosstalk.The measured average relative errors are 7.08%,8.62%,7.15%,and 7.59%at 9.3,9.6,10.3,and 10.6μm,respectively.Simultaneously,the broadband full polarization imaging capability of the device is also verified.This work is expected to have potential applications in wavefront detection,remote sensing,light-field imaging,and so forth.
基金National Natural Science Foundation of China under contact Nos.61622508,61622509,and 61675208.
文摘Optical camouflage is a magical capability of animals as first noticed in 1794 by Erasmus Darwin in Zoonomia,but current biomimetic camouflage strategies cannot be readily applied in complex environments involving multispectral and in particular multi-polarization detection.Here we develop a plasmonic approach toward broadband infrared polarimetric crypsis,where the polarized thermal emission near the pseudo-Brewster angle is the main signal source and no existing polarizing camouflage technique has been discovered in nature.Based on all-metallic subwavelength structures,an electrodynamic resistance-reduction mechanism is proposed to avoid the significant polarization-dependent infrared absorption/radiation.It is also found that the structured metal surface presents giant extrinsic anisotropy regarding the phase shift between orthogonal polarization states,which helps to realize ultrahigh-efficiency and tunable polarization conversion in an unprecedented manner.Finally,we note that the catenary optical theory may provide a useful means to explain and predict these unusual performances.
基金supported by 973 Program of China (2013CBA01700)National Natural Science Funds (61622508, 61575032)
文摘Spin-orbit optical phenomena pertain to the wider class of electromagnetic effects originating from the interaction of the photon spin with the spatial structure and propagation characteristics of an optical wave,mediated by suitable optical media.There are many emerging photonic applications of spin-orbit interactions(SOI)of light,such as control of the optical wave propagation via the spin,enhanced optical manipulation,and generation of structured optical fields.Unfortunately,current applications are based on symmetric SOI,that is,the behaviours of polarized photons with two opposite spins are opposite,leading to the limit of spin-based multiplexers.The symmetry of SOI can be broken in our proposed metasurfaces,consisting of spatially varying birefringence,which can arbitrarily and independently build SOI for two opposite spins without reduction of optical energy usage.We obtain three kinds of dual-functional metasurfaces at visible and infrared wavelengths with high efficiency.Our concept of generation of asymmetric SOI for two spins,using anisotropic metasurfaces,will open new degrees of freedoms for building new types of spin-controlled multifunctional shared-aperture devices for the generation of complex structured optical fields.
基金We acknowledge the financial support by the National Natural Science Foundation of China under contact Nos.61622508,61622509,and 61575201.
文摘Dispersion control is crucial in optical systems,and chromatic aberration is an important factor affecting imaging quality in imaging systems.Due to the inherent property of materials,dispersion engineering is complex and needs to trade off other aberration in traditional ways.Although metasurface offers an effective method to overcome these limits and results in well-engineered dispersion,off-axis dispersion control is still a challenging topic.In this paper,we design a single-layer metalens which is capable of focusing at three wavelengths(473 nm,532 nm,and 632 nm)with different incident angles(0°,-17°and 17°)into the same point.We also demonstrate that this metalens can provide an alternative for the bulky color synthetic prism in a 3-chips digital micromirror device(DMD)laser projection system.Through this approach,various off-axis dispersion controlling optical devices could be realized.
文摘1.Introduction Artificial intelligence(AI)is committed to the realization of machine-borne intelligence.The technologies underpinning AI have made huge leaps in the past decade,bringing exciting applications such as language understanding,vision recognition,and intelligent digital assistants.However,contemporary AI systems are good at specific predefined tasks and are unable to learn by themselves from data or from experience,intuitive reasoning,and adaptation.
基金We acknowledge the financial support by 973 Program of China under con-tract No. 2013CBA01700 and the National Natural Science Foundation of China under contract No. 61622509 and 61575203.
基金supported by the 973 Program of China (2013CBA01700)the National Natural Science Funds (61138002)
文摘In this paper,we demonstrate an auto accurate alignment method to align mask-substrate in the prototype of plasmonic lithography(PL),which is essential for multilayer nanostructure fabrication with high resolution,low cost,high efficiency,and high throughput,such as circuit manufacturing and other applications.We obtained an alignment signal with sensitivity better than 20 nm by using the Moiréfringe image.However,only using the Moiréfringes cannot guarantee the alignment of the mask and the substrate because the Moiréfringe repeats itself when the mask and substrate are offset by a fixed displacement.To eliminate the ambiguity,boxes and the crosses alignment marks are designed beside the grating marks on the substrate and the mask,respectively.A two-step alignment scheme including coarse alignment and fine alignment is explored in the auto alignment system.In the stage of coarse alignment,the edge detection algorithm based on Canny operator is adopted to detect the edges image effectively.In the process of fine alignment,Fourier transform based on Moiréfringe image is obtained to improve the alignment accuracy.In addition,experimental results of overlay indicate that PL can obtain sub-100 nm alignment accuracy over an area of 1 cm^2 using the proposed two-step alignment scheme.Via the substrate-mask mismatch compensation,better stages and precise environment control,it is expected that much higher overlay accuracy is feasible.
文摘The current metadata modeling techniques can not meet the needs of knowledge conception expression, knowledge organization, and metadata semantic consistency in geological domain. This paper introduces ontology and integrates this theory to geological domain metadata modeling. It adopts the first order logic equivalent algorithm and defines the metadata extended model as a quaternion group which is consists of geological term set, geological term definition set, attribute definition set and instance set. It also provides the formal description of each set. Finally the five steps for building geological domain metadata extended model are given. The result presents that this model not only provides the content standards for geological domain knowledge representation and knowledge organization, but also provides the basis for geological domain multi-source data and historical data integration and application in semantic consistency.
文摘Optics is an ancient and vibrant subject with a rich his-tory of thousands of years.Since Maxwell discovered that light is an electromagnetic wave,optics has always been accompanied by electricity.Optics and opto-electronics play a vital role in many key fields related to the devel-opment and progress of mankind,such as energy,infor-mation,internet,astronomy,and medicine,etc.Many large-scale scientific projects,ranging from laser nuclear fusion to gravitational wave detection,from large-aperture telescopes to lithography equipment,are mainly based on opto-electronic science.
基金supported by the National Key Research and Development Program of China(Grant No.2023YFB2805800)the National Natural Science Foundation of China(Grant Nos.62175242,and U20A20217)the Sichuan Science and Technology Program(Grant No.2021ZYCD002)。
文摘Independent manipulation of transmitted and reflected light fields is a key technology for the realization of multifunctional optical applications,which can be implemented based on multilayered plasmonic or supercell subwavelength structures.However,the former is not suitable for the optical bands,while the latter is insufficient in generating large phase gradients.Here,an adjoint-optimization-based inverse design methodology is proposed,which utilizes the polarization-selective local interference between individual meta-atoms and enables monolayer dielectric metasurfaces to decouple the wavefront of transmitted and reflected optical fields.Moreover,this methodology serves to mitigate the aperiodic electromagnetic crosstalk inherent between adjacent meta-atoms,consequently leading to a significant enhancement in the performance of meta-devices.We analyzed the physical mechanism of adjoint optimization and proposed the concept of phase factors,highlighting their importance in the rapid inverse design of meta-devices—an aspect often overlooked in previous research.To demonstrate the feasibility and robustness of our method,we optimize monolayer metasurfaces with different initial structures.These devices efficiently focus and deflect x-linearly and y-linearly polarized incident light in transmission and reflection spaces,respectively.Overall,this methodology holds immense potential for designing multifunctional,high-performing metasurfaces that meet multiple constraints,opening up broad prospects for applications.
基金National Natural Science Foundation of China(61875253,62222513,U20A20217)National Key Research and Development Program of China(SQ2021YFA1401000)+1 种基金Sichuan Science and Technology Program(2021ZYCD001)Youth Innovation Promotion Association of the Chinese Academy of Sciences(2019371)。
文摘Multi-dimensional optical imaging systems that simultaneously gather intensity,depth,polarimetric,and spectral information have numerous applications in medical sciences,robotics,and surveillance.Nevertheless,most current approaches require mechanical moving parts or multiple modulation processes and thus suffer from long acquisition time,high system complexity,or low sampling resolution.Here,a methodology to build snapshot multi-dimensional lensless imaging is proposed by combining planar-optics and computational technology,benefiting from sufficient flexibilities in optical engineering and robust information reconstructions.Specifically,a liquid crystal diffuser based on geometric phase modulation is designed to simultaneously encode the spatial,spectral,and polarization information of an object into a snapshot detected speckle pattern.At the same time,a post-processing algorithm acts as a special decoder to recover the hidden information in the speckle with the independent and unique point spread function related to the position,wavelength,and chirality.With the merits of snapshot acquisition,multi-dimensional perception ability,simple optical configuration,and compact device size,our approach can find broad potential applications in object recognition and classification.
基金National Natural Science Foundation of China(62105338,62171087)Sichuan Science and Technology Program(2021JDJQ0023,2021ZYCD001)+1 种基金Fundamental Research Funds for the Central Universities(ZYGX2019J003)Science and Technology Commission of Shanghai Municipality(SKLSFO2020-05)。
文摘Optical chaotic signals emitted from an external-cavity feedback or injected laser diode enable small-signal information concealment in a noise-like carrier for secure optical communications.Due to the chaotic bandwidth limitation resulting from intrinsic relaxation oscillation frequency of lasers,multiplexing of optical chaotic signal,such as wavelength division multiplexing in fiber,is a typical candidate for high-capacity secure applications.However,to our best knowledge,the utilization of the spatial dimension of optical chaos for free-space secure communication has not yet been reported.Here,we experimentally demonstrate a free-space all-optical chaotic communication system that simultaneously enhances transmission capacity and security by orbital angular momentum(OAM)multiplexing.Optical chaotic signals with two different OAM modes totally carrying 20 Gbps on-off keying signals are secretly transmitted over a 2 m free-space link,where the channel crosstalk of OAM modes is less than-20 d B,with the mode spacing no less than 3.The receiver can extract valid information only when capturing approximately 92.5% of the OAM beam and correctly demodulating the corresponding mode.Bit error rate below the 7%hard-decision forward error correction threshold of 3.8×10^(-3)can be achieved for the intended recipient.Moreover,a simulated weak turbulence is introduced to comprehensively analyze the influence on the system performance,including channel crosstalk,chaotic synchronization,and transmission performance.Our work may inspire structured light application in optical chaos and pave a new way for developing future high-capacity free-space chaotic secure communication systems.
文摘The 4 m diameter SiC aspheric mirror emerges due to a series of technological breakthroughs in blank mirror preparation,asphere fabrication,and testing,as well as cladding and coating,laying the groundwork for future research into large SiC mirrors for astronomical observation.
基金supported by the National Natural Science Foundation of China(62175242,U20A20217,and 62222513)the Sichuan Science and Technology Program(2021ZYCD002)the China Postdoctoral Science Foundation(2021T140670 and 2020M680153).
文摘Wide-angle imaging and spectral detection play vital roles in tasks such as target tracking,object classification,and anti-camouflage.However,limited by their intrinsically different architectures,as determined by frequency dispersion requirements,their simultaneous implementation in a shared-aperture system is difficult.Here,we propose a novel concept to realize reconfigurable dual-mode detection based on electrical-control tunable metasurfaces.As a proof-of-concept demonstration,the simultaneous implementation of wide-angle imaging and polarization-spectral detection in a miniature sharedaperture meta-optical system is realized for the first time via the electrical control of cascaded catenary-like metasurfaces.The proposed system supports the imaging(spectral)resolution of approximately 27.8 line-pairs per millimeter(lp·mm^(-1);~80 nm)for an imaging(spectral)mode from 8 to 14 μm.This system also bears a large field of view of about 70°,enabling multi-target recognition in both modes.This work may promote the miniaturization of multifunctional optical systems,including spectrometers and polarization imagers,and illustrates the potential industrial applications of meta-optics in biomedicine,security,space exploration,and more.