Secret sharing is a promising technology for information encryption by splitting the secret information into different shares.However,the traditional scheme suffers from information leakage in decryption process since...Secret sharing is a promising technology for information encryption by splitting the secret information into different shares.However,the traditional scheme suffers from information leakage in decryption process since the amount of available information channels is limited.Herein,we propose and demonstrate an optical secret sharing framework based on the multi-dimensional multiplexing liquid crystal(LC)holograms.The LC holograms are used as spatially separated shares to carry secret images.The polarization of the incident light and the distance between different shares are served as secret keys,which can significantly improve the information security and capacity.Besides,the decryption condition is also restricted by the applied external voltage due to the variant diffraction efficiency,which further increases the information security.In implementation,an artificial neural network(ANN)model is developed to carefully design the phase distribution of each LC hologram.With the advantage of high security,high capacity and simple configuration,our optical secret sharing framework has great potentials in optical encryption and dynamic holographic display.展开更多
Orbital angular momentum(OAM),described by an azimuthal phase term expej lθT,has unbound orthogonal states with different topological charges l.Therefore,with the explosive growth of global communication capacity,esp...Orbital angular momentum(OAM),described by an azimuthal phase term expej lθT,has unbound orthogonal states with different topological charges l.Therefore,with the explosive growth of global communication capacity,especially for short-distance optical interconnects,light-carrying OAM has proved its great potential to improve transmission capacity and spectral efficiency in the space-division multiplexing system due to its orthogonality,security,and compatibility with other techniques.Meanwhile,100-m freespace optical interconnects become an alternative solution for the“last mile”problem and provide interbuilding communication.We experimentally demonstrate a 260-m secure optical interconnect using OAM multiplexing and 16-ary quadrature amplitude modulation(16-QAM)signals.We study the beam wandering,power fluctuation,channel cross talk,bit-error-rate performance,and link security.Additionally,we also investigate the link performance for 1-to-9 multicasting at the range of 260 m.Considering that the power distribution may be affected by atmospheric turbulence,we introduce an offline feedback process to make it flexibly controllable.展开更多
The in-band full-duplex(IBFD)wireless system is a promising candidate for 6G and beyond,as it can double data throughput and enormously lower transmission latency by supporting simultaneous in-band transmission and re...The in-band full-duplex(IBFD)wireless system is a promising candidate for 6G and beyond,as it can double data throughput and enormously lower transmission latency by supporting simultaneous in-band transmission and reception of signals.Enabling IBFD systems requires a substantial mitigation of a transmitter(Tx)’s strong self-interference(SI)signal into the receiver(Rx)channel.However,current state-ofthe-art approaches to tackle this challenge are inefficient in terms of performance,cost,and complexity,hindering the commercialization of IBFD techniques.In this work,we devise and demonstrate an innovative approach to realize IBFD systems that exhibit superior performance with a low-cost and lesscomplex architecture in an all-passive module.Our scheme is based on meticulously combining polarization-division multiplexing(PDM)with ferromagnetic nonreciprocity to achieve ultra-high isolation between Tx and Rx channels.Such an unprecedented conception has become feasible thanks to a concurrent dual-mode circulator—a new component introduced for the first time—as a key feature of our module,and a dual-mode waveguide that transforms two orthogonally polarized waves into two orthogonal waveguide modes.In addition,we propose a unique passive tunable secondary SI cancellation(SIC)mechanism,which is embedded within the proposed module and boosts the isolation over a relatively broad bandwidth.We report,solely in the analog domain,experimental isolation levels of 50,70,and 80 dB over 340,101,and 33 MHz bandwidth at the center frequency of interest,respectively,with excellent tuning capability.Furthermore,the module is tested in two real IBFD scenarios to assess its performance in connection with Tx-to-Rx leakage and modulation error in the presence of a Tx’s strong interference signal.展开更多
The use of orbital angular momentum(OAM)as an independent dimension for information encryption has garnered considerable attention.However,the multiplexing capacity of OAM is limited,and there is a need for additional...The use of orbital angular momentum(OAM)as an independent dimension for information encryption has garnered considerable attention.However,the multiplexing capacity of OAM is limited,and there is a need for additional dimensions to enhance storage capabilities.We propose and implement orbital angular momentum lattice(OAML)multiplexed holography.The vortex lattice(VL)beam comprises three adjustable parameters:the rotation angle of the VL,the angle between the wave normal and the z axis,which determines the VL’s dimensions,and the topological charge.Both the rotation angle and the VL’s dimensions serve as supplementary encrypted dimensions,contributing azimuthally and radially,respectively.We investigate the mode selectivity of OAML and focus on the aforementioned parameters.Through experimental validation,we demonstrate the practical feasibility of OAML multiplexed holography across multiple dimensions.This groundbreaking development reveals new possibilities for the advancement of practical information encryption systems.展开更多
The interleaving/multiplexing technique was used to realize a 200?MHz real time data acquisition system. Two 100?MHz ADC modules worked parallelly and every ADC plays out data in ping pang fashion. The design improv...The interleaving/multiplexing technique was used to realize a 200?MHz real time data acquisition system. Two 100?MHz ADC modules worked parallelly and every ADC plays out data in ping pang fashion. The design improved the system conversion rata to 200?MHz and reduced the speed of data transporting and storing to 50?MHz. The high speed HDPLD and ECL logic parts were used to control system timing and the memory address. The multi layer print board and the shield were used to decrease interference produced by the high speed circuit. The system timing was designed carefully. The interleaving/multiplexing technique could improve the system conversion rata greatly while reducing the speed of external digital interfaces greatly. The design resolved the difficulties in high speed system effectively. The experiment proved the data acquisition system is stable and accurate.展开更多
Herein,an attention-grabbing and up-to-date review related to major multiplexing techniques is presented which in-cludes wavelength division multiplexing(WDM),polarization division multiplexing(PDM),space division mul...Herein,an attention-grabbing and up-to-date review related to major multiplexing techniques is presented which in-cludes wavelength division multiplexing(WDM),polarization division multiplexing(PDM),space division multiplexing(SDM),mode division multiplexing(MDM)and orbital angular momentum multiplexing(OAMM).Multiplexing is a mech-anism by which multiple signals are combined into a shared channel used to showcase the maximum capacity of the op-tical links.However,it is critical to develop hybrid multiplexing methods to allow enhanced channel numbers.In this re-view,we have also included hybrid multiplexing techniques such as WDM-PDM,WDM-MDM and PDM-MDM.It is prob-able to attain N×M channels by utilizing N wavelengths and M guided-modes by simply utilizing hybrid WDM-MDM(de)multiplexers.To the best of our knowledge,this review paper is one of its kind which has highlighted the most prom-inent and recent signs of progress in multiplexing techniques in one place.展开更多
Flat optical elements have attracted enormous attentions and act as promising candidates for the next generation of optical components.As one of the most outstanding representatives,liquid crystal(LC)has been widely a...Flat optical elements have attracted enormous attentions and act as promising candidates for the next generation of optical components.As one of the most outstanding representatives,liquid crystal(LC)has been widely applied in flat panel display industries and inspires the wavefront modulation with the development of LC alignment techniques.However,most LC elements perform only one type of optical manipulation and are difficult to realize the multifunctionality and light integration.Here,flat multifunctional liquid crystal elements(FMLCEs),merely composed of anisotropic LC molecules with space-variant orientations,are presented for multichannel information manipulation by means of polarization,space and wavelength multiplexing.Specifically,benefiting from the unique light response with the change of the incident polarization,observation plane,and working wavelength,a series of FMLCEs are demonstrated to achieve distinct near-and far-field display functions.The proposed strategy takes full advantage of basic optical parameters as the decrypted keys to improve the information capacity and security,and we expect it to find potential applications in information encryption,optical anti-counterfeiting,virtual/augmented reality,etc.展开更多
基金support from the National Natural Science Foundation of China (No.62005164,62222507,62175101,and 62005166)the Shanghai Natural Science Foundation (23ZR1443700)+3 种基金Shuguang Program of Shanghai Education Development Foundation and Shanghai Municipal Education Commission (23SG41)the Young Elite Scientist Sponsorship Program by CAST (No.20220042)Science and Technology Commission of Shanghai Municipality (Grant No.21DZ1100500)the Shanghai Municipal Science and Technology Major Project,and the Shanghai Frontiers Science Center Program (2021-2025 No.20).
文摘Secret sharing is a promising technology for information encryption by splitting the secret information into different shares.However,the traditional scheme suffers from information leakage in decryption process since the amount of available information channels is limited.Herein,we propose and demonstrate an optical secret sharing framework based on the multi-dimensional multiplexing liquid crystal(LC)holograms.The LC holograms are used as spatially separated shares to carry secret images.The polarization of the incident light and the distance between different shares are served as secret keys,which can significantly improve the information security and capacity.Besides,the decryption condition is also restricted by the applied external voltage due to the variant diffraction efficiency,which further increases the information security.In implementation,an artificial neural network(ANN)model is developed to carefully design the phase distribution of each LC hologram.With the advantage of high security,high capacity and simple configuration,our optical secret sharing framework has great potentials in optical encryption and dynamic holographic display.
基金supported by the National Natural Science Foundation of China (Grant Nos.62125503,62261160388,and 62101198)the Natural Science Foundation of Hubei Province of China (Grant Nos.2021CFB011 and 2023AFA028)+2 种基金the Key R&D Program of Hubei Province of China (Grant Nos.2020BAB001 and 2021BAA024)Shenzhen Science and Technology Program (Grant No.JCYJ20200109114018750)the Innovation Project of Optics Valley Laboratory (Grant Nos.OVL2021BG004 and OVL2023ZD004).
文摘Orbital angular momentum(OAM),described by an azimuthal phase term expej lθT,has unbound orthogonal states with different topological charges l.Therefore,with the explosive growth of global communication capacity,especially for short-distance optical interconnects,light-carrying OAM has proved its great potential to improve transmission capacity and spectral efficiency in the space-division multiplexing system due to its orthogonality,security,and compatibility with other techniques.Meanwhile,100-m freespace optical interconnects become an alternative solution for the“last mile”problem and provide interbuilding communication.We experimentally demonstrate a 260-m secure optical interconnect using OAM multiplexing and 16-ary quadrature amplitude modulation(16-QAM)signals.We study the beam wandering,power fluctuation,channel cross talk,bit-error-rate performance,and link security.Additionally,we also investigate the link performance for 1-to-9 multicasting at the range of 260 m.Considering that the power distribution may be affected by atmospheric turbulence,we introduce an offline feedback process to make it flexibly controllable.
基金supported by a Natural Sciences and Engineering Research Council(NSERC)-sponsored Industrial Research Chair program,an NSERC Discovery Grantin part by the Fonds de recherche du Québec Nature et technologies(FRQNT)Doctoral Fellowship of Amir Afshani funded by the Government of Québec Province.
文摘The in-band full-duplex(IBFD)wireless system is a promising candidate for 6G and beyond,as it can double data throughput and enormously lower transmission latency by supporting simultaneous in-band transmission and reception of signals.Enabling IBFD systems requires a substantial mitigation of a transmitter(Tx)’s strong self-interference(SI)signal into the receiver(Rx)channel.However,current state-ofthe-art approaches to tackle this challenge are inefficient in terms of performance,cost,and complexity,hindering the commercialization of IBFD techniques.In this work,we devise and demonstrate an innovative approach to realize IBFD systems that exhibit superior performance with a low-cost and lesscomplex architecture in an all-passive module.Our scheme is based on meticulously combining polarization-division multiplexing(PDM)with ferromagnetic nonreciprocity to achieve ultra-high isolation between Tx and Rx channels.Such an unprecedented conception has become feasible thanks to a concurrent dual-mode circulator—a new component introduced for the first time—as a key feature of our module,and a dual-mode waveguide that transforms two orthogonally polarized waves into two orthogonal waveguide modes.In addition,we propose a unique passive tunable secondary SI cancellation(SIC)mechanism,which is embedded within the proposed module and boosts the isolation over a relatively broad bandwidth.We report,solely in the analog domain,experimental isolation levels of 50,70,and 80 dB over 340,101,and 33 MHz bandwidth at the center frequency of interest,respectively,with excellent tuning capability.Furthermore,the module is tested in two real IBFD scenarios to assess its performance in connection with Tx-to-Rx leakage and modulation error in the presence of a Tx’s strong interference signal.
基金supported by the Guangdong Major Project of Basic and Applied Basic Research (Grant No.2020B0301030009)the National Natural Science Foundation of China (Grant Nos.61935013,62375181,and 61975133)+1 种基金the Shenzhen Science and Technology Program (Grant No.JCYJ20200109114018750)the Shenzhen Peacock Plan (Grant No.KQTD20170330110444030).
文摘The use of orbital angular momentum(OAM)as an independent dimension for information encryption has garnered considerable attention.However,the multiplexing capacity of OAM is limited,and there is a need for additional dimensions to enhance storage capabilities.We propose and implement orbital angular momentum lattice(OAML)multiplexed holography.The vortex lattice(VL)beam comprises three adjustable parameters:the rotation angle of the VL,the angle between the wave normal and the z axis,which determines the VL’s dimensions,and the topological charge.Both the rotation angle and the VL’s dimensions serve as supplementary encrypted dimensions,contributing azimuthally and radially,respectively.We investigate the mode selectivity of OAML and focus on the aforementioned parameters.Through experimental validation,we demonstrate the practical feasibility of OAML multiplexed holography across multiple dimensions.This groundbreaking development reveals new possibilities for the advancement of practical information encryption systems.
文摘The interleaving/multiplexing technique was used to realize a 200?MHz real time data acquisition system. Two 100?MHz ADC modules worked parallelly and every ADC plays out data in ping pang fashion. The design improved the system conversion rata to 200?MHz and reduced the speed of data transporting and storing to 50?MHz. The high speed HDPLD and ECL logic parts were used to control system timing and the memory address. The multi layer print board and the shield were used to decrease interference produced by the high speed circuit. The system timing was designed carefully. The interleaving/multiplexing technique could improve the system conversion rata greatly while reducing the speed of external digital interfaces greatly. The design resolved the difficulties in high speed system effectively. The experiment proved the data acquisition system is stable and accurate.
基金financially supported by the Russian Foundation for Basic Research(grant No.18-29-20045)for WDM,MDM and hybrid WDM-MDM,WDM-PDM sectionsthe Russian Science Foundation(grant No.21-79-20075)for PDM,OAMM and hybrid PDM-MDM sectionsthe Ministry of Science and Higher Education of the Russian Federation under the FSRC"Crystallography and Photonics"of the Russian Academy of Sciences(the state task No.007-GZ/Ch3363/26)for comparative analysis.
文摘Herein,an attention-grabbing and up-to-date review related to major multiplexing techniques is presented which in-cludes wavelength division multiplexing(WDM),polarization division multiplexing(PDM),space division multiplexing(SDM),mode division multiplexing(MDM)and orbital angular momentum multiplexing(OAMM).Multiplexing is a mech-anism by which multiple signals are combined into a shared channel used to showcase the maximum capacity of the op-tical links.However,it is critical to develop hybrid multiplexing methods to allow enhanced channel numbers.In this re-view,we have also included hybrid multiplexing techniques such as WDM-PDM,WDM-MDM and PDM-MDM.It is prob-able to attain N×M channels by utilizing N wavelengths and M guided-modes by simply utilizing hybrid WDM-MDM(de)multiplexers.To the best of our knowledge,this review paper is one of its kind which has highlighted the most prom-inent and recent signs of progress in multiplexing techniques in one place.
基金the supports from the National Natural Science Foundation of China (61905073, 61835004, 62134001, 61905031, 62105263, 62275077)Fundamental Research Fund for the Central Universities (531118010189, 310202011qd002)+1 种基金the support from Xi’an Science and Technology Association Youth Talent Support Project (095920211306)the Postdoctoral Innovation Talent Support Program of China (BX20220388)
文摘Flat optical elements have attracted enormous attentions and act as promising candidates for the next generation of optical components.As one of the most outstanding representatives,liquid crystal(LC)has been widely applied in flat panel display industries and inspires the wavefront modulation with the development of LC alignment techniques.However,most LC elements perform only one type of optical manipulation and are difficult to realize the multifunctionality and light integration.Here,flat multifunctional liquid crystal elements(FMLCEs),merely composed of anisotropic LC molecules with space-variant orientations,are presented for multichannel information manipulation by means of polarization,space and wavelength multiplexing.Specifically,benefiting from the unique light response with the change of the incident polarization,observation plane,and working wavelength,a series of FMLCEs are demonstrated to achieve distinct near-and far-field display functions.The proposed strategy takes full advantage of basic optical parameters as the decrypted keys to improve the information capacity and security,and we expect it to find potential applications in information encryption,optical anti-counterfeiting,virtual/augmented reality,etc.
