Optical orbital angular momentum(OAM)mode multiplexing has emerged as a promising technique for boosting communication capacity.However,most existing studies have concentrated on channel(de)-multiplexing,overlooking t...Optical orbital angular momentum(OAM)mode multiplexing has emerged as a promising technique for boosting communication capacity.However,most existing studies have concentrated on channel(de)-multiplexing,overlooking the critical aspect of channel routing.This challenge involves the reallocation of multiplexed OAM modes across both spatial and temporal domains—a vital step for developing versatile communication networks.To address this gap,we introduce a novel approach based on the time evolution of OAM modes,utilizing the orthogonal conversion and diffractive modulation capabilities of unitary transformations.This approach facilitates high-dimensional orthogonal transformations of OAM mode vectors,altering both the propagation direction and the spatial location.Using Fresnel diffraction matrices as unitary operators,it manipulates the spatial locations of light beams during transmission,breaking the propagation invariance and enabling temporal evolution.As a demonstration,we have experimentally implemented the deep routing of four OAM modes within two distinct time sequences.Achieving an average diffraction efficiency above 78.31%,we have successfully deep-routed 4.69 Tbit-s^(-1)quadrature phase-shift keying(QPSK)signals carried by four multiplexed OAM channels,with a bit error rate below 10^(-6).These results underscore the efficacy of our routing strategy and its promising prospects for practical applications.展开更多
Optical vortices,characterized by their infinite orthogonal eigenmodes—such as orbital angular momentum(OAM)and cylindrical vector beam(CVB)modes—offer unprecedented opportunities for advancing optical communication...Optical vortices,characterized by their infinite orthogonal eigenmodes—such as orbital angular momentum(OAM)and cylindrical vector beam(CVB)modes—offer unprecedented opportunities for advancing optical communication systems.The core components of these systems—mode(de)modulation,mode processing,and mode transmission—are fundamental to the construction and networking of OAM/CVB mode-based communication networks.They significantly influence signal encoding,enhance channel capacity,and facilitate signal interconnection and transmission.We explore the historical development and recent advancements in optical vortex-based communication systems from these three critical perspectives.We systematically summarize the normative definitions and research progress related to key concepts such as mode multiplexing and routing.We also demonstrate the performance of these systems in terms of communication capacity,bit error rate,and more.Furthermore,we examine the substantial challenges and future prospects in this field,with the aim of offering cutting-edge insights that will facilitate the advancement and practical implementation of optical communication networks leveraging optical vortex modes.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
基金the National Natural Science Foundation of China(62271322)the Guangdong Basic and Applied Basic Research Foundation(2022A1515011003 and 2023A1515030152)the Shenzhen Science and Technology Program(JCYJ20210324095610027 and JCYJ20210324095611030).
文摘Optical orbital angular momentum(OAM)mode multiplexing has emerged as a promising technique for boosting communication capacity.However,most existing studies have concentrated on channel(de)-multiplexing,overlooking the critical aspect of channel routing.This challenge involves the reallocation of multiplexed OAM modes across both spatial and temporal domains—a vital step for developing versatile communication networks.To address this gap,we introduce a novel approach based on the time evolution of OAM modes,utilizing the orthogonal conversion and diffractive modulation capabilities of unitary transformations.This approach facilitates high-dimensional orthogonal transformations of OAM mode vectors,altering both the propagation direction and the spatial location.Using Fresnel diffraction matrices as unitary operators,it manipulates the spatial locations of light beams during transmission,breaking the propagation invariance and enabling temporal evolution.As a demonstration,we have experimentally implemented the deep routing of four OAM modes within two distinct time sequences.Achieving an average diffraction efficiency above 78.31%,we have successfully deep-routed 4.69 Tbit-s^(-1)quadrature phase-shift keying(QPSK)signals carried by four multiplexed OAM channels,with a bit error rate below 10^(-6).These results underscore the efficacy of our routing strategy and its promising prospects for practical applications.
基金supported by the National Natural Science Foundation of China(Grant Nos.62271322,61935013,62375181,62335019,62475294,and 62475290)the Guangdong Major Project of Basic Research(Grant No.2020B0301030009)+5 种基金the Basic and Applied Basic Research Foundation of Guangdong(Grant Nos.2023A1515030152 and 2021B1515020093)the Shenzhen Peacock Plan(Grant No.KQTD20170330110444030)the Scientific Instrument Developing Project of Shenzhen University(Grant No.2023YQ001)the Shenzhen University 2035 Initiative(Grant No.2023B004)the Natural Science Foundation of Top Talent of SZTU(Grant No.GDRC202204)the Fundamental Research Funds for the Central Universities,Sun Yat-sen University(Grant No.24xkjc015)。
文摘Optical vortices,characterized by their infinite orthogonal eigenmodes—such as orbital angular momentum(OAM)and cylindrical vector beam(CVB)modes—offer unprecedented opportunities for advancing optical communication systems.The core components of these systems—mode(de)modulation,mode processing,and mode transmission—are fundamental to the construction and networking of OAM/CVB mode-based communication networks.They significantly influence signal encoding,enhance channel capacity,and facilitate signal interconnection and transmission.We explore the historical development and recent advancements in optical vortex-based communication systems from these three critical perspectives.We systematically summarize the normative definitions and research progress related to key concepts such as mode multiplexing and routing.We also demonstrate the performance of these systems in terms of communication capacity,bit error rate,and more.Furthermore,we examine the substantial challenges and future prospects in this field,with the aim of offering cutting-edge insights that will facilitate the advancement and practical implementation of optical communication networks leveraging optical vortex modes.
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.
