A new compound based on immobilizing of Pd6(RuL3)8(BF4)28 (L=2-(pyridin-3-yl)-1H-imidazo [4,5-f][1,10]-phenanthroline) cage (MOC-16) on g-C3N4 was synthesized. Infrared spectrum and powder X-ray diffraction were used ...A new compound based on immobilizing of Pd6(RuL3)8(BF4)28 (L=2-(pyridin-3-yl)-1H-imidazo [4,5-f][1,10]-phenanthroline) cage (MOC-16) on g-C3N4 was synthesized. Infrared spectrum and powder X-ray diffraction were used to characterize structure of hybrid MOC-16/g-C3N4, as well as UV-vis absorption spectrum and X-ray photoelectron spectroscopy were carried out to unveil photocatalytic mechanism. With the introduction of MOC-16, the absorption edge of MOC-16/g-C3N4 in UV-vis spectrum extended apparently to long-wavelength region compared with pristine g-C3N4. H2 evolution yielded with MOC-16/g-C3N4 in aqueous solution containing TEOA was much higher than that with RuL3/g-C3N4, Pd/RuL3/g-C3N4 and mixture of MOC-16 and g-C3N4, showing that the octahedral cage structure with high-efficient electron transfer and the interface interaction between MOC-16 and g-C3N4 were significant for improvement of H2 evolution.展开更多
Advancements in orbital angular momentum (OAM) mode-multiplexing communication networks requiretunable mode filters for selective channel demultiplexing and downloading. In this study, we propose a spatialdepth-depend...Advancements in orbital angular momentum (OAM) mode-multiplexing communication networks requiretunable mode filters for selective channel demultiplexing and downloading. In this study, we propose a spatialdepth-dependent mode transformation strategy for the tunable filtering of OAM modes. By integrating the spiralphase and lens phase modulations, we achieved mode conversions that varied with the transmission depth,enabling selective demultiplexing in predetermined axial planes. This approach facilitates tunable mode filteringby adjusting spatial depths. As a proof of concept, we fabricated a mode filter using two-photon polymerizationlithography (TPL) technology, successfully filtering five OAM modes with mode crosstalk below −10.9 dB.Additionally, the filter was applied in a mode-multiplexing communication link, achieving tunable demultiplexingof five mode channels with bit error rates below 10^(−6). These results highlight the efficacy and flexibilityof our strategy for OAM mode filtering and offer promising insights for the development of mode-multiplexingcommunication networks and channel interconnections.展开更多
Micro/nanorobots(MNRs)capable of performing tasks at the micro-and nanoscale hold great promise for applications in cutting-edge fields such as biomedical engineering,environmental engineering,and microfabrication.To ...Micro/nanorobots(MNRs)capable of performing tasks at the micro-and nanoscale hold great promise for applications in cutting-edge fields such as biomedical engineering,environmental engineering,and microfabrication.To cope with the intricate and dynamic environments encountered in practical applications,the development of high performance MNRs is crucial.They have evolved from single-material,single-function,and simple structure to multi-material,multi-function,and complex structure.However,the design and manufacturing of high performance MNRs with complex multi-material three-dimensional structures at the micro-and nanoscale pose significant challenges that cannot be addressed by conventional serial design strategies and single-process manufacturing methods.The material-interface-structure-function/performance coupled design methods and the additive/formative/subtractive composite manufacturing methods offer the opportunity to design and manufacture MNRs with multimaterials and complex structures under multi-factor coupling,thus paving the way for the development of high performance MNRs.In this paper,we take the three core capabilities of MNRs—mobility,controllability,and load capability—as the focal point,emphasizing the coupled design methods oriented towards their function/performance and the composite manufacturing methods for their functional structures.The limitations of current investigation are also discussed,and our envisioned future directions for design and manufacture of MNRs are shared.We hope that this review will provide a framework template for the design and manufacture of high performance MNRs,serving as a roadmap for researchers interested in this area.展开更多
In this paper, the Penman-Monteith method was applied to evaluate the reference crop evapotranspiration. A reliable estimation of the reference evapotranspiration (ETo) is of critical importance and required accurate ...In this paper, the Penman-Monteith method was applied to evaluate the reference crop evapotranspiration. A reliable estimation of the reference evapotranspiration (ETo) is of critical importance and required accurate estimates to close the water balance. The aim of this paper is estimating the reference evapotranspiration (ETo) as preliminary to use for groundwater modeling in the area. Based on FAO-Penman-Monteith method, ETo calculator software was applied. Meteorological data within this study were obtained from two gauges stations (Xing ping and Wu gong) and available literatures. The results indicated that the values of ETo for a period (1981-2009)—29 years—in two stations approximately the same. Specifically, is ranged between 0.4 - 6.9 mm /day, 0.4 - 6.7 mm/day and the average value is 2.6 mm/ day, 2.6 mm/day in Xing ping and Wu gong respectively. In addition, the maximum values were occurred in summer season (May, June and July). The result also found that the correlation coefficient ≈ 1. Moreover, “ETo” was increasing by recent years. The reference crop evapotranspiration for some crops were calculated.展开更多
On-chip multidimensional multiplexing has shown considerable potential for enhancing transmission capacity and developing communication networks in integrated optical systems.Micro-ring resonators,which utilize the wa...On-chip multidimensional multiplexing has shown considerable potential for enhancing transmission capacity and developing communication networks in integrated optical systems.Micro-ring resonators,which utilize the wavelength-dependent whispering gallery resonance mechanism and feature customizable cavity lengths,offer inherent advantages for accurate wavelength filtering.These characteristics make them promising candidates for wavelength multiplexers.However,a significant challenge arises from the mismatch in the effective refractive index between orthogonal linear polarizations,which introduces complexities to polarization channel multiplexing and impedes progress in on-chip multidimensional multiplexing that integrates both wavelength and polarization channels.In this work,we propose a double-layer adiabatic structureconnected micro-ring resonator(AMRR)with vertical refractive index asymmetry,demonstrating its utility in multidimensional(de)multiplexers.Our approach enables polarization division multiplexing(PDM)by facilitating polarization rotation between transverse electric and transverse magnetic polarizations through polarization hybridization.The(de)multiplexing of both wavelength and polarization channels is achieved by controlling the incident light direction and filtering the resonance wavelength within the micro-ring resonator.As a proof of concept,we successfully transmitted 144 Gbit/s QPSK-OFDM signals and achieved bit error rates below the forward error correction threshold at-19 d Bm using the proposed multidimensional(de)multiplexer,which accommodates 3 wavelengths and 2 polarizations.Our design,which leverages the AMRR for simultaneous(de)multiplexing of wavelength and polarization channels,not only overcomes the limitation of traditional micro-ring resonators in implementing PDM,but also reduces the footprint of the multidimensional(de)multiplexer to 27μm×219μm,an order of magnitude smaller compared to conventional designs.展开更多
Orbital angular momentum(OAM)modes provide an additional orthogonal physical dimension,offering transformative potential for enhancing optical communication capacity.Despite significant progress in mode multiplexing,t...Orbital angular momentum(OAM)modes provide an additional orthogonal physical dimension,offering transformative potential for enhancing optical communication capacity.Despite significant progress in mode multiplexing,the development of robust communication networks faces persistent challenges,particularly in effectively routing and controlling these multiplexed channels among network nodes.To tackle these dilemmas,we propose a rotatable diffractive neural network(R-DNN)strategy and demonstrate its capability for port-controllable OAM mode routing.By leveraging the correlation between the orthogonal evolution of OAM modes in free space and phase modulations during propagation,the R-DNN precisely shapes the spatial evolution of mode fields through multiple rotatable phase layers,enabling efficient routing to specific output ports.This approach exploits the interaction of secondary wavelets with the relative states of the rotatable layers,allowing on-demand control of mode evolution paths and enhancing routing flexibility.As a proof of concept,we developed a tri-functional router that successfully directs three OAM modes to individually controllable output ports.This router achieves an average intermode crosstalk of less than−16.4 dB across three functional states,one-dimensional,two-dimensional,and cross-connected switching,while supporting the routing of 5.85 Tbit/s quadrature phase-shift keying signals.These results highlight the R-DNN’s effectiveness in achieving precise and controllable OAM mode manipulation,paving the way for advanced applications in mode-multiplexed communication networks and beyond.展开更多
Optical logical operations demonstrate the key role of optical digital computing,which can perform general-purpose calculations and possess fast processing speed,low crosstalk,and high throughput.The logic states usua...Optical logical operations demonstrate the key role of optical digital computing,which can perform general-purpose calculations and possess fast processing speed,low crosstalk,and high throughput.The logic states usually refer to linear momentums that are distinguished by intensity distributions,which blur the discrimination boundary and limit its sustainable applications.Here,we introduce orbital angular momentum(OAM)mode logical operations performed by optical diffractive neural networks(ODNNs).Using the OAM mode as a logic state not only can improve the parallel processing ability but also enhance the logic distinction and robustness of logical gates owing to the mode infinity and orthogonality.ODNN combining scalar diffraction theory and deep learning technology is designed to independently manipulate the mode and spatial position of multiple OAM modes,which allows for complex multilight modulation functions to respond to logic inputs.We show that few-layer ODNNs successfully implement the logical operations of AND,OR,NOT,NAND,and NOR in simulations.The logic units of XNOR and XOR are obtained by cascading the basic logical gates of AND,OR,and NOT,which can further constitute logical half-adder gates.Our demonstrations may provide a new avenue for optical logical operations and are expected to promote the practical application of optical digital computing.展开更多
Black phosphorus(BP), with thickness-dependent direct energy bandgaps(0.3–2 eV), shows an enhanced nonlinear optical response at near-and mid-infrared wavelengths. In this paper, we present experimentally multilayer ...Black phosphorus(BP), with thickness-dependent direct energy bandgaps(0.3–2 eV), shows an enhanced nonlinear optical response at near-and mid-infrared wavelengths. In this paper, we present experimentally multilayer BP flakes coated on microfiber(BCM) as a saturable absorber with a modulation depth of 16% and a saturable intensity of 6.8 MW∕cm^2. After inserting BCM into an Er-doped fiber ring laser, a stable dual-wavelength Q-switched state with central wavelengths of 1542.4 nm and 1543.2 nm(with wavelength spacing as small as 0.8 nm) is obtained with the aid of two cascaded fiber Bragg gratings as a coarse wavelength selector.Moreover, single-wavelength Q-switched operation at 1542.4 nm or 1543.2 nm is also realized, which can be switched between the two wavelengths flexibly just by adjusting the intracavity birefringence. These results suggest that BP combined with the cascaded fiber gratings can provide a simple and feasible candidate for a multiwavelength fiber laser. Our fiber laser may have potential applications in terahertz generation, laser radar,and so on.展开更多
Photonic spin Hall efect(SHE)provides new opportunities for achieving spin-based photonics applications.However,flexibly manipulating the spin-dependent sltting(SDS)of photonic SHE and imposing extra phase modulation ...Photonic spin Hall efect(SHE)provides new opportunities for achieving spin-based photonics applications.However,flexibly manipulating the spin-dependent sltting(SDS)of photonic SHE and imposing extra phase modulation on the two spin components are always a challenge.Here,a controllable SHE mechanism based on phase function construction is reported.It is conduded that the phases with specific functional structures performing a coordinate translation are equivalent to integrating a gradient phase to the original phases.Hence,the original phase can be used for independent phase modulation,and the gradient phase originating from the co-ordinate translation is capable of manipulating the SDS.A metasurface with Pancharatnam-Berry phase that can impose conjugate phases to the two spin components of light is fabricated to verify this mechanism.By shifing the light position,the SDS is continuously manipulated in the visible region,which is successfully used for detecting the polarization llipticity.The extra phase modulation is also performed with the original phase and thus enables measuring singular beams.It is anticipated that the controllable SHE manipulation method may open new avenues in the fields of spin photonics,optical sensing,optical communications,etc.展开更多
Metasurfaces composed of spatially arranged ultrathin subwavelength elements are promising photonic devices for manipulating optical wavefronts,with potential applications in holography,metalens,and multiplexing commu...Metasurfaces composed of spatially arranged ultrathin subwavelength elements are promising photonic devices for manipulating optical wavefronts,with potential applications in holography,metalens,and multiplexing communications.Finding microstructures that meet light modulation requirements is always a challenge in designing metasurfaces,where parameter sweep,gradient-based inverse design,and topology optimization are the most commonly used design methods in which the massive electromagnetic iterations require the design computational cost and are sometimes prohibitive.Herein,we propose a fast inverse design method that combines a physicsbased neural network surrogate model(NNSM)with an optimization algorithm.The NNSM,which can generate an accurate electromagnetic response from the geometric topologies of the meta-atoms,is constructed for electromagnetic iterations,and the optimization algorithm is used to search for the on-demand meta-atoms from the phase library established by the NNSM to realize an inverse design.This method addresses two important problems in metasurface design:fast and accurate electromagnetic wave phase prediction and inverse design through a single phase-shift value.As a proof-of-concept,we designed an orbital angular momentum(de)multiplexer based on a phase-type metasurface,and 200 Gbit/s quadrature-phase shift-keying signals were successfully transmitted with a bit error rate approaching 1.67×10^(-6).Because the design is mainly based on an optimization algorithm,it can address the“one-to-many”inverse problem in other micro/nano devices such as integrated photonic circuits,waveguides,and nano-antennas.展开更多
The progress of on-chip optical communication relies on integrated multi-dimensional mode(de)multiplexers to enhance communication capacity and establish comprehensive networks.However,existing multi-dimensional(de)mu...The progress of on-chip optical communication relies on integrated multi-dimensional mode(de)multiplexers to enhance communication capacity and establish comprehensive networks.However,existing multi-dimensional(de)multiplexers,involving modes and wavelengths,face limitations due to their reliance on single-directional total internal reflection and multi-level mode conversion based on directional coupling principles.These constraints restrict their potential for full-duplex functionality and highly integrated communication.We solve these problems by introducing a photonic-like crystal-connected bidirectional micro-ring resonator array(PBMRA)and apply it to duplex mode-wavelength multiplexing communication.The directional independence of total internal reflection and the cumulative effect of the subwavelength-scale pillar within the single-level photonic crystal enable bidirectional mode and wavelength multiplexed signals to transmit among multi-pair nodes without interference,improving on-chip integration in single-level mode conversion.As a proof of concept,we fabricated a nine-channel bidirectional multi-dimensional(de)multiplexer,featuring three wavelengths and three TE modes,compactly housed within a footprint of 80μm×80μm,which efficiently transmits QPSK-OFDM signals at a rate of 216 Gbit/s,achieving a bit error rate lower than 10^(-4).Leveraging the co-ring transmission characteristic and the orthogonality of the mode-wavelength channel,this(de)multiplexer also enables a doubling of communication capacity using two physical transmission channels.展开更多
Macrocyclic CTV-Br3 reacted with the linear benzene-1,4-diboronic acid and 1,4-diethynylbenzene via Suzuki and Sonogashira-Hagihara coupling reactions producing the rigid porous materials CTV-CMP-1 and CTV-CMP-2. The ...Macrocyclic CTV-Br3 reacted with the linear benzene-1,4-diboronic acid and 1,4-diethynylbenzene via Suzuki and Sonogashira-Hagihara coupling reactions producing the rigid porous materials CTV-CMP-1 and CTV-CMP-2. The porous materials have good thermal and chemical stability. The Brunauer-Emmet-Teller specific surface areas of CTV-CMP-1 and CTV-CMP-2 are 314 and 218 cm2·g^-1, respectively. Physical properties of the porous materi- als were investigated, CTV-CMP-1 showed moderate hydrogen adsorption about 0.81 wt% at 1.13 bar while CTV-CMP-2 showed lower hydrogen adsorption about 0.51 wt%. These materials are analogs to activated carbons which could be potentially used in gas separation and organic compound adsorption.展开更多
The advancement of integrated optical communication networks necessitates the deployment of on-chip beam splitters for efficient signal interconnections at network nodes.However,the pursuit of micron-scale beam splitt...The advancement of integrated optical communication networks necessitates the deployment of on-chip beam splitters for efficient signal interconnections at network nodes.However,the pursuit of micron-scale beam splitting with large corners and reducing the device footprint to boost connection flexibility often results in phase mismatches.These mismatches,which stem from radiation modes and backward scattering,pose significant obstacles in creating highly integrated and interference-resistant connections.To address this,we introduce a solution based on the topological valley-contrasting state generated by photonic crystals with opposing valley Chern numbers,manifested in a harpoon-shaped structure designed to steer the splitting channels.This approach enables adiabatic mode field evolution over large corners,capitalizing on the robust phase modulation capabilities and topological protection provided by the subwavelength-scale valley-contrasting state.Our demonstration reveals that beam splitters with large corners of 60°,90°,and 120°exhibit insertion loss fluctuations below 2.7 dB while maintaining a minimal footprint of 8.8μm×8.8μm.As a practical demonstration,these devices facilitate three-channel signal connections,successfully transmitting quadrature phase shift keying signals at 3.66 Tbit/s with bit error rates below the forward error correction threshold,demonstrating performance comparable to that in defects scenarios.By harnessing the unidirectional excitation feature,we anticipate significant enhancements in the capabilities of signal distribution and connection networks through a daisy chain configuration.展开更多
Hybrid neural network models are effective in analyzing time-series data by combining the strengths of neural networks and differential equation models.Although most studies have focused on linear hybrid models,few ha...Hybrid neural network models are effective in analyzing time-series data by combining the strengths of neural networks and differential equation models.Although most studies have focused on linear hybrid models,few have examined nonlinear problems.This work explores the potential of a hybrid nonlinear epidemic neural network in predicting the correct infection function of an epidemic model.We design a novel loss function by combining bifurcation theory and mean-squared error loss to ensure the trainability of the hybrid model.Additionally,we identify unique existence conditions that support ordinary differential equations for estimating the correct infection function.Moreover,numerical experiments using the Runge-Kutta method confirm our proposed model's soundness both on our synthetic data and the real COVID-19 data.展开更多
基金supported by the National Natural Science Foundation of China(21875293,21821003,21890380,21720102007,21572280)the Natural Science Foundation of Guangdong Province(2016A030313268)+2 种基金the STP Project of Guangzhou(201804010386,201707010114)the Fundamental Research Funds for the Central Universities(17lgzd18,17lgzd01)the Research Fund Program of Key Laboratory of Fuel Cell Technology of Guangdong Province~~
文摘A new compound based on immobilizing of Pd6(RuL3)8(BF4)28 (L=2-(pyridin-3-yl)-1H-imidazo [4,5-f][1,10]-phenanthroline) cage (MOC-16) on g-C3N4 was synthesized. Infrared spectrum and powder X-ray diffraction were used to characterize structure of hybrid MOC-16/g-C3N4, as well as UV-vis absorption spectrum and X-ray photoelectron spectroscopy were carried out to unveil photocatalytic mechanism. With the introduction of MOC-16, the absorption edge of MOC-16/g-C3N4 in UV-vis spectrum extended apparently to long-wavelength region compared with pristine g-C3N4. H2 evolution yielded with MOC-16/g-C3N4 in aqueous solution containing TEOA was much higher than that with RuL3/g-C3N4, Pd/RuL3/g-C3N4 and mixture of MOC-16 and g-C3N4, showing that the octahedral cage structure with high-efficient electron transfer and the interface interaction between MOC-16 and g-C3N4 were significant for improvement of H2 evolution.
文摘Advancements in orbital angular momentum (OAM) mode-multiplexing communication networks requiretunable mode filters for selective channel demultiplexing and downloading. In this study, we propose a spatialdepth-dependent mode transformation strategy for the tunable filtering of OAM modes. By integrating the spiralphase and lens phase modulations, we achieved mode conversions that varied with the transmission depth,enabling selective demultiplexing in predetermined axial planes. This approach facilitates tunable mode filteringby adjusting spatial depths. As a proof of concept, we fabricated a mode filter using two-photon polymerizationlithography (TPL) technology, successfully filtering five OAM modes with mode crosstalk below −10.9 dB.Additionally, the filter was applied in a mode-multiplexing communication link, achieving tunable demultiplexingof five mode channels with bit error rates below 10^(−6). These results highlight the efficacy and flexibilityof our strategy for OAM mode filtering and offer promising insights for the development of mode-multiplexingcommunication networks and channel interconnections.
基金National Natural Science Foundation of China(Nos.52125505,U23A20637)。
文摘Micro/nanorobots(MNRs)capable of performing tasks at the micro-and nanoscale hold great promise for applications in cutting-edge fields such as biomedical engineering,environmental engineering,and microfabrication.To cope with the intricate and dynamic environments encountered in practical applications,the development of high performance MNRs is crucial.They have evolved from single-material,single-function,and simple structure to multi-material,multi-function,and complex structure.However,the design and manufacturing of high performance MNRs with complex multi-material three-dimensional structures at the micro-and nanoscale pose significant challenges that cannot be addressed by conventional serial design strategies and single-process manufacturing methods.The material-interface-structure-function/performance coupled design methods and the additive/formative/subtractive composite manufacturing methods offer the opportunity to design and manufacture MNRs with multimaterials and complex structures under multi-factor coupling,thus paving the way for the development of high performance MNRs.In this paper,we take the three core capabilities of MNRs—mobility,controllability,and load capability—as the focal point,emphasizing the coupled design methods oriented towards their function/performance and the composite manufacturing methods for their functional structures.The limitations of current investigation are also discussed,and our envisioned future directions for design and manufacture of MNRs are shared.We hope that this review will provide a framework template for the design and manufacture of high performance MNRs,serving as a roadmap for researchers interested in this area.
文摘In this paper, the Penman-Monteith method was applied to evaluate the reference crop evapotranspiration. A reliable estimation of the reference evapotranspiration (ETo) is of critical importance and required accurate estimates to close the water balance. The aim of this paper is estimating the reference evapotranspiration (ETo) as preliminary to use for groundwater modeling in the area. Based on FAO-Penman-Monteith method, ETo calculator software was applied. Meteorological data within this study were obtained from two gauges stations (Xing ping and Wu gong) and available literatures. The results indicated that the values of ETo for a period (1981-2009)—29 years—in two stations approximately the same. Specifically, is ranged between 0.4 - 6.9 mm /day, 0.4 - 6.7 mm/day and the average value is 2.6 mm/ day, 2.6 mm/day in Xing ping and Wu gong respectively. In addition, the maximum values were occurred in summer season (May, June and July). The result also found that the correlation coefficient ≈ 1. Moreover, “ETo” was increasing by recent years. The reference crop evapotranspiration for some crops were calculated.
基金supported by the National Natural Science Foundation of China(Grant Nos.62271322,62331004,and 62222501)Guangdong Basic and Applied Basic Research Foundation(Grant No.2023A1515030152)+5 种基金the Science and Technology Project of Shenzhen(Grant No.ZDSYS201707271014468)Shenzhen Science and Technology Program(Grant No.JCYJ20240813143018024)the Natural Science Foundation of Top Talent of SZTU(Grant No.GDRC202204)Qianxinan Prefecture Science and Technology Plan Project(Grant No.2023123)the Scientific Research Fund Project of Minzu Normal University of Xingyi(Grant No.23XYZD07)Guizhou Province Youth Science and Technology Talent Development Project(Qian Jiaoji[2024]No.244)。
文摘On-chip multidimensional multiplexing has shown considerable potential for enhancing transmission capacity and developing communication networks in integrated optical systems.Micro-ring resonators,which utilize the wavelength-dependent whispering gallery resonance mechanism and feature customizable cavity lengths,offer inherent advantages for accurate wavelength filtering.These characteristics make them promising candidates for wavelength multiplexers.However,a significant challenge arises from the mismatch in the effective refractive index between orthogonal linear polarizations,which introduces complexities to polarization channel multiplexing and impedes progress in on-chip multidimensional multiplexing that integrates both wavelength and polarization channels.In this work,we propose a double-layer adiabatic structureconnected micro-ring resonator(AMRR)with vertical refractive index asymmetry,demonstrating its utility in multidimensional(de)multiplexers.Our approach enables polarization division multiplexing(PDM)by facilitating polarization rotation between transverse electric and transverse magnetic polarizations through polarization hybridization.The(de)multiplexing of both wavelength and polarization channels is achieved by controlling the incident light direction and filtering the resonance wavelength within the micro-ring resonator.As a proof of concept,we successfully transmitted 144 Gbit/s QPSK-OFDM signals and achieved bit error rates below the forward error correction threshold at-19 d Bm using the proposed multidimensional(de)multiplexer,which accommodates 3 wavelengths and 2 polarizations.Our design,which leverages the AMRR for simultaneous(de)multiplexing of wavelength and polarization channels,not only overcomes the limitation of traditional micro-ring resonators in implementing PDM,but also reduces the footprint of the multidimensional(de)multiplexer to 27μm×219μm,an order of magnitude smaller compared to conventional designs.
基金supported by the National Natural Science Foundation of China(Grant Nos.62271322,62331004,and 62222501)the Guangdong Basic and Applied Basic Research Foundation(Grant No.2023A1515030152)+1 种基金the Science and Technology Project of Shenzhen(Grant No.ZDSYS201707271014468)the Natural Science Foundation of Top Talent of SZTU(Grant No.GDRC202204)。
文摘Orbital angular momentum(OAM)modes provide an additional orthogonal physical dimension,offering transformative potential for enhancing optical communication capacity.Despite significant progress in mode multiplexing,the development of robust communication networks faces persistent challenges,particularly in effectively routing and controlling these multiplexed channels among network nodes.To tackle these dilemmas,we propose a rotatable diffractive neural network(R-DNN)strategy and demonstrate its capability for port-controllable OAM mode routing.By leveraging the correlation between the orthogonal evolution of OAM modes in free space and phase modulations during propagation,the R-DNN precisely shapes the spatial evolution of mode fields through multiple rotatable phase layers,enabling efficient routing to specific output ports.This approach exploits the interaction of secondary wavelets with the relative states of the rotatable layers,allowing on-demand control of mode evolution paths and enhancing routing flexibility.As a proof of concept,we developed a tri-functional router that successfully directs three OAM modes to individually controllable output ports.This router achieves an average intermode crosstalk of less than−16.4 dB across three functional states,one-dimensional,two-dimensional,and cross-connected switching,while supporting the routing of 5.85 Tbit/s quadrature phase-shift keying signals.These results highlight the R-DNN’s effectiveness in achieving precise and controllable OAM mode manipulation,paving the way for advanced applications in mode-multiplexed communication networks and beyond.
基金National Natural Science Foundation of China(12047539,61805149,62101334)Guangdong Basic and Applied Basic Research Foundation(2019A1515111153,2020A1515011392,2020A1515110572,2021A1515011762)+4 种基金Shenzhen Fundamental Research Program(JCYJ20180507182035270,JCYJ20200109144001800)Science and Technology Project of Shenzhen(GJHZ20180928160407303)Shenzhen Universities Stabilization Support Program(SZWD2021013)Shenzhen Excellent Scientific and Technological Innovative Talent Training Program(RCBS20200714114818094)China Postdoctoral Science Foundation(2020M682867)。
文摘Optical logical operations demonstrate the key role of optical digital computing,which can perform general-purpose calculations and possess fast processing speed,low crosstalk,and high throughput.The logic states usually refer to linear momentums that are distinguished by intensity distributions,which blur the discrimination boundary and limit its sustainable applications.Here,we introduce orbital angular momentum(OAM)mode logical operations performed by optical diffractive neural networks(ODNNs).Using the OAM mode as a logic state not only can improve the parallel processing ability but also enhance the logic distinction and robustness of logical gates owing to the mode infinity and orthogonality.ODNN combining scalar diffraction theory and deep learning technology is designed to independently manipulate the mode and spatial position of multiple OAM modes,which allows for complex multilight modulation functions to respond to logic inputs.We show that few-layer ODNNs successfully implement the logical operations of AND,OR,NOT,NAND,and NOR in simulations.The logic units of XNOR and XOR are obtained by cascading the basic logical gates of AND,OR,and NOT,which can further constitute logical half-adder gates.Our demonstrations may provide a new avenue for optical logical operations and are expected to promote the practical application of optical digital computing.
基金National Natural Science Foundation of China(NSFC)(61490710,61505122,61775142)Science and Technology Planning Project of Guangdong Province(2016B050501005)+1 种基金Specialized Research Fund for the Shenzhen Strategic Emerging Industries Development(JCYJ20170412105812811)Natural Science Foundation of SZU(2017018)
文摘Black phosphorus(BP), with thickness-dependent direct energy bandgaps(0.3–2 eV), shows an enhanced nonlinear optical response at near-and mid-infrared wavelengths. In this paper, we present experimentally multilayer BP flakes coated on microfiber(BCM) as a saturable absorber with a modulation depth of 16% and a saturable intensity of 6.8 MW∕cm^2. After inserting BCM into an Er-doped fiber ring laser, a stable dual-wavelength Q-switched state with central wavelengths of 1542.4 nm and 1543.2 nm(with wavelength spacing as small as 0.8 nm) is obtained with the aid of two cascaded fiber Bragg gratings as a coarse wavelength selector.Moreover, single-wavelength Q-switched operation at 1542.4 nm or 1543.2 nm is also realized, which can be switched between the two wavelengths flexibly just by adjusting the intracavity birefringence. These results suggest that BP combined with the cascaded fiber gratings can provide a simple and feasible candidate for a multiwavelength fiber laser. Our fiber laser may have potential applications in terahertz generation, laser radar,and so on.
基金Program of Fundamental Rescarch of Science and Technology Planning Project of Shenzhen Munipality(JCYJ20180507182035270)Science and Technology Planning Project of Guangdong Province(2016B050501005)+3 种基金Science and Technology Project of Shenzhen(ZDSYS201707271014468)International Collaborative Laboratory of 2D Materials for Opeoelectronics Science and Technology(2DMOST2018003)National Natural Science Foundation of China(61805087,61805149)Natural Science Foundation of Guangdong Province(2016A030310065,2018A030313368,2020A1515011392).
文摘Photonic spin Hall efect(SHE)provides new opportunities for achieving spin-based photonics applications.However,flexibly manipulating the spin-dependent sltting(SDS)of photonic SHE and imposing extra phase modulation on the two spin components are always a challenge.Here,a controllable SHE mechanism based on phase function construction is reported.It is conduded that the phases with specific functional structures performing a coordinate translation are equivalent to integrating a gradient phase to the original phases.Hence,the original phase can be used for independent phase modulation,and the gradient phase originating from the co-ordinate translation is capable of manipulating the SDS.A metasurface with Pancharatnam-Berry phase that can impose conjugate phases to the two spin components of light is fabricated to verify this mechanism.By shifing the light position,the SDS is continuously manipulated in the visible region,which is successfully used for detecting the polarization llipticity.The extra phase modulation is also performed with the original phase and thus enables measuring singular beams.It is anticipated that the controllable SHE manipulation method may open new avenues in the fields of spin photonics,optical sensing,optical communications,etc.
基金Shenzhen Peacock Plan(20180521645C,20180921273B)China Postdoctoral Science Foundation(2020M682867)+5 种基金Shenzhen Excellent Scientific and Technological Innovative Talent Training Program(RCBS20200714114818094)Shenzhen Universities Stabilization Support Program(SZWD2021013)Science and Technology Project of Shenzhen(GJHZ20180928160407303)Shenzhen Fundamental Research Program(JCYJ20210324095611030,JCYJ20210324095610027)Basic and Applied Basic Research Foundation of Guangdong Province(2019A1515111153,2020A1515011392,2020A1515110572,2021A1515011762)National Natural Science Foundation of China(12047539,61805149,62101334)。
文摘Metasurfaces composed of spatially arranged ultrathin subwavelength elements are promising photonic devices for manipulating optical wavefronts,with potential applications in holography,metalens,and multiplexing communications.Finding microstructures that meet light modulation requirements is always a challenge in designing metasurfaces,where parameter sweep,gradient-based inverse design,and topology optimization are the most commonly used design methods in which the massive electromagnetic iterations require the design computational cost and are sometimes prohibitive.Herein,we propose a fast inverse design method that combines a physicsbased neural network surrogate model(NNSM)with an optimization algorithm.The NNSM,which can generate an accurate electromagnetic response from the geometric topologies of the meta-atoms,is constructed for electromagnetic iterations,and the optimization algorithm is used to search for the on-demand meta-atoms from the phase library established by the NNSM to realize an inverse design.This method addresses two important problems in metasurface design:fast and accurate electromagnetic wave phase prediction and inverse design through a single phase-shift value.As a proof-of-concept,we designed an orbital angular momentum(de)multiplexer based on a phase-type metasurface,and 200 Gbit/s quadrature-phase shift-keying signals were successfully transmitted with a bit error rate approaching 1.67×10^(-6).Because the design is mainly based on an optimization algorithm,it can address the“one-to-many”inverse problem in other micro/nano devices such as integrated photonic circuits,waveguides,and nano-antennas.
基金Natural Science Foundation of Top Talent of SZTU(GDRC202204)Shenzhen Science and Technology Program(JCYJ20210324095610027)+1 种基金Guangdong Basic and Applied Basic Research Foundation(2023A1515030152)National Natural Science Foundation of China(62271322)。
文摘The progress of on-chip optical communication relies on integrated multi-dimensional mode(de)multiplexers to enhance communication capacity and establish comprehensive networks.However,existing multi-dimensional(de)multiplexers,involving modes and wavelengths,face limitations due to their reliance on single-directional total internal reflection and multi-level mode conversion based on directional coupling principles.These constraints restrict their potential for full-duplex functionality and highly integrated communication.We solve these problems by introducing a photonic-like crystal-connected bidirectional micro-ring resonator array(PBMRA)and apply it to duplex mode-wavelength multiplexing communication.The directional independence of total internal reflection and the cumulative effect of the subwavelength-scale pillar within the single-level photonic crystal enable bidirectional mode and wavelength multiplexed signals to transmit among multi-pair nodes without interference,improving on-chip integration in single-level mode conversion.As a proof of concept,we fabricated a nine-channel bidirectional multi-dimensional(de)multiplexer,featuring three wavelengths and three TE modes,compactly housed within a footprint of 80μm×80μm,which efficiently transmits QPSK-OFDM signals at a rate of 216 Gbit/s,achieving a bit error rate lower than 10^(-4).Leveraging the co-ring transmission characteristic and the orthogonality of the mode-wavelength channel,this(de)multiplexer also enables a doubling of communication capacity using two physical transmission channels.
基金the National Natural Science Foundation of China，the Major State Basic Research Development Program of China，the Chinese Academy of Sciences
文摘Macrocyclic CTV-Br3 reacted with the linear benzene-1,4-diboronic acid and 1,4-diethynylbenzene via Suzuki and Sonogashira-Hagihara coupling reactions producing the rigid porous materials CTV-CMP-1 and CTV-CMP-2. The porous materials have good thermal and chemical stability. The Brunauer-Emmet-Teller specific surface areas of CTV-CMP-1 and CTV-CMP-2 are 314 and 218 cm2·g^-1, respectively. Physical properties of the porous materi- als were investigated, CTV-CMP-1 showed moderate hydrogen adsorption about 0.81 wt% at 1.13 bar while CTV-CMP-2 showed lower hydrogen adsorption about 0.51 wt%. These materials are analogs to activated carbons which could be potentially used in gas separation and organic compound adsorption.
基金supported by the National Natural Science Foundation of China(Grant No.62271322)Guangdong Basic and Applied Basic Research Foundation(Grant No.2023A1515030152)+3 种基金Shenzhen Science and Technology Program(Grant No.JCYJ20210324095610027)Natural Science Foundation of Top Talent of SZTU(Grant No.GDRC202204)Qianxinan Prefecture Science and Technology Plan Project(Grant No.2023123)Scientific Research Fund Project of Minzu Normal University of Xingyi(Grant No.23XYZD07)。
文摘The advancement of integrated optical communication networks necessitates the deployment of on-chip beam splitters for efficient signal interconnections at network nodes.However,the pursuit of micron-scale beam splitting with large corners and reducing the device footprint to boost connection flexibility often results in phase mismatches.These mismatches,which stem from radiation modes and backward scattering,pose significant obstacles in creating highly integrated and interference-resistant connections.To address this,we introduce a solution based on the topological valley-contrasting state generated by photonic crystals with opposing valley Chern numbers,manifested in a harpoon-shaped structure designed to steer the splitting channels.This approach enables adiabatic mode field evolution over large corners,capitalizing on the robust phase modulation capabilities and topological protection provided by the subwavelength-scale valley-contrasting state.Our demonstration reveals that beam splitters with large corners of 60°,90°,and 120°exhibit insertion loss fluctuations below 2.7 dB while maintaining a minimal footprint of 8.8μm×8.8μm.As a practical demonstration,these devices facilitate three-channel signal connections,successfully transmitting quadrature phase shift keying signals at 3.66 Tbit/s with bit error rates below the forward error correction threshold,demonstrating performance comparable to that in defects scenarios.By harnessing the unidirectional excitation feature,we anticipate significant enhancements in the capabilities of signal distribution and connection networks through a daisy chain configuration.
基金This work was funded by the GDAS'Project of Science and Technology Development(2021GDASYL-20210103089)Postdoctoral Research Foundation of China(2021M690747)+4 种基金National Natural Science Foundation of China(12001139,61877049 and 11991023)Science and Technology Program of Guangzhou(202007040007)GDAS'Project of Science and Technology Development(2019GDASYL-0502007)Guangdong Provincial Rural Revitalization Strategy Special Fund Project(2019KJ138)Guangdong Basic and Applied Basic Research Foundation(2019A1515110503).
文摘Hybrid neural network models are effective in analyzing time-series data by combining the strengths of neural networks and differential equation models.Although most studies have focused on linear hybrid models,few have examined nonlinear problems.This work explores the potential of a hybrid nonlinear epidemic neural network in predicting the correct infection function of an epidemic model.We design a novel loss function by combining bifurcation theory and mean-squared error loss to ensure the trainability of the hybrid model.Additionally,we identify unique existence conditions that support ordinary differential equations for estimating the correct infection function.Moreover,numerical experiments using the Runge-Kutta method confirm our proposed model's soundness both on our synthetic data and the real COVID-19 data.
