High-capacity on-chip optical transmitters and receivers are crucial for data transmissions.Currently,advanced multiplexing technologies,including wavelength division multiplexing(WDM),mode-division multiplexing(MDM),...High-capacity on-chip optical transmitters and receivers are crucial for data transmissions.Currently,advanced multiplexing technologies,including wavelength division multiplexing(WDM),mode-division multiplexing(MDM),and polarization-divisionmultiplexing(PDM)have been developed to greatly enhance the link capacity.In this paper,monolithically integrated silicon photonic transmitter and receiver with an ultra-high-capacity density of 37.0 Tbps/cm^(2) were proposed and demonstrated by introducing hybrid multiplexers and arrayed modulators/photodetectors.For the demonstrated transmitter/receiver chips,there are five wavelength channels and four mode channels with dual polarizations involved,while all these channels have low excess losses of 1 to 2 dB and low crosstalk less than−15 dB.Finally,all 20 channels are able to work with 50 Gbps on–off keying(OOK)signals per channel,achieving a total capacity of 1T-bps within an ultra-compact chip size of 0.032 cm^(2) for transmitters and 0.022 cm^(2) for receivers.展开更多
Dealing with the increase in data workloads and network complexity requires efficient selective manipulation of any channels in hybrid mode-/wavelength-division multiplexing(MDM/WDM)systems.A reconfigurable optical ad...Dealing with the increase in data workloads and network complexity requires efficient selective manipulation of any channels in hybrid mode-/wavelength-division multiplexing(MDM/WDM)systems.A reconfigurable optical add-drop multiplexer(ROADM)using special modal field redistribution is proposed and demonstrated to enable the selective access of any mode-/wavelength-channels.With the assistance of the subwavelength grating structures,the launched modes are redistributed to be the supermodes localized at different regions of the multimode bus waveguide.Microring resonators are placed at the corresponding side of the bus waveguide to have specific evanescent coupling of the redistributed supermodes,so that any mode-/wavelength-channel can be added/dropped by thermally tuning the resonant wavelength.As an example,a ROADM for the case with three mode-channels is designed with low excess losses of<0.6,0.7,and 1.3 dB as well as low cross talks of<−26.3,−28.5,and−39.3 dB for the TE0,TE1,and TE2 modes,respectively,around the central wavelength of 1550 nm.The data transmission of 30 Gbps∕channel is also demonstrated successfully.The present ROADM provides a promising route for data switching/routing in hybrid MDM/WDM systems.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
Orbital angular momentum(OAM)beams,characterized by a helical phase structure and phase singularity,have emerged as a powerful resource for high-capacity optical communications through mode-division multiplexing(MDM)....Orbital angular momentum(OAM)beams,characterized by a helical phase structure and phase singularity,have emerged as a powerful resource for high-capacity optical communications through mode-division multiplexing(MDM).Traditional OAM multiplexing systems operating solely in the spatial domain face significant challenges,including increased system complexity,inter-modal crosstalk,and limited scalability.Recent advances have explored hybrid multiplexing schemes combining OAM with wavelength or polarization degrees of freedom,demonstrating Pbit/s level transmission capacities.However,these systems predominantly rely on continuous-wave lasers and external modulators,which constrain their applicability in challenging environments,whereas pulsed lasers provide superior peak power,enhanced transmission robustness,and the potential for implementation of OAM lasers,which generally emit pulsed OAM beams.Here,we report an OAM-based spatiotemporal multiplexing(OAM-STM)technique that synergistically implements pulsed OAM beams with a diffractive deep neural network(D^(2)NN)and optical fiber delay lines to project spatial mode information into the temporal domain.This approach leverages the full potential of pulsed laser sources by activating the underutilized time dimension,thereby overcoming the repetition-rate bottleneck and enhancing channel throughput.We experimentally demonstrate an OAM-based spatiotemporal demultiplexer achieving demultiplexing speed limited only by the bandwidth of the photodiode if OAM generation is fast enough.In the meantime,the architecture is intrinsically compatible with high-repetition-rate OAM sources,offering the entire system the scalability to GHz rates.This work establishes a foundational framework for high-speed,all-optical,and high-capacity OAM-STM systems,with promising implications for free-space optical communication,underwater communication links,and other complex environments.展开更多
The aim of this study was to look in depth at the relationship between meiotic anomalies and male infertility, such as the determination of the chromosomes involved or the correlation with patient features. For this p...The aim of this study was to look in depth at the relationship between meiotic anomalies and male infertility, such as the determination of the chromosomes involved or the correlation with patient features. For this purpose, a total of 31 testicular tissue samples from individuals consulting for fertility problems were analyzed. Metaphase I cells were evaluated using a sequential methodology combining Leishman stained procedures and multiplex fluorescence in situ hybridization protocols. The number of chromosomal units and chiasmata count per bivalent were established and a hierarchical cluster analysis of the individuals was performed. The relationship of the seminogram and the karyotype over recombination were evaluated using Poisson regression models. Results obtained in this study show a significant percentage of infertile individuals with altered meiotic behavior, mostly specified as a reduction in chiasmata count in medium and large chromosomes, the presence of univalents, and the observation of tetraploid metaphases. Moreover, the number and the type of anomalies were found to be different between cells of the same individual, suggesting the coexistence of cell lines with normal meiotic behavior and cell lines with abnormalities. In addition, chromosomal abnormalities in metaphase I are significantly associated with oligozoospermia and/or polymorphic karyotype variants.展开更多
A critical gap currently exists in systematic understanding and experimental validation of the role of astrocytes in neurovascular coupling and their functional links with other brain cells.Despite a broad selection o...A critical gap currently exists in systematic understanding and experimental validation of the role of astrocytes in neurovascular coupling and their functional links with other brain cells.Despite a broad selection of functional neuroimaging tools for multi-scale brain interrogations,no methodology currently exists that can discern responses from neural and glial cells while simultaneously mapping the associated hemodynamic activity on a large scale.We present a hybrid multiplexed fluorescence and magnetic resonance imaging(HyFMRI)platform for measuring neuronal and astrocytic activity registered to concurrently recorded brain-wide hemodynamic responses.It features a fiberscope-based imaging system for multichannel fluorescence and optical intrinsic signal recordings and a custom surface radiofrequency coil,which are incorporated into the bore of a preclinical magnetic resonance imaging(MRI)scanner.We used HyFMRI to study peripheral-stimulus-evoked brain responses in mice differentially labeled with RCaMP and GCaMP genetically-encoded calcium indicators.Stimulation-evoked neuronal responses displayed the fastest kinetics and highest activation amplitude followed by astrocytic signals and the hemodynamic responses simultaneously recorded with functional MRI.In addition,the activation traces from neurons and astrocytes exhibited high linear correlation,thus providing direct evidence of astrocytic mediation in neurovascular coupling.This newly developed capacity to capture cell-type-specific calcium signaling alongside whole-brain hemodynamics enables the simultaneous investigation of neuro-glial-vascular interactions in health and disease.HyFMRI thus expands the current neuroimaging toolbox for a wide range of studies into synaptic plasticity,neural circuitry,brain function and disorders.展开更多
Non-orthogonal time-frequency division multiplexing （NTFDM） transmission scheme has been proposed to further improve the bandwidth efficiency and overcome the drawbacks of the conventional orthogonal frequency divis...Non-orthogonal time-frequency division multiplexing （NTFDM） transmission scheme has been proposed to further improve the bandwidth efficiency and overcome the drawbacks of the conventional orthogonal frequency division multiplexing （OFDM） method. Based on such approach, the fast signal detection algorithm, semidefinite programming （SDP） detection, has been studied. As the coefficient matrix tends to be ill conditioned, the modified SDP algorithm combined with successive interference cancellation （SIC） has been developed. The improved algorithm is a good tradeoff between performance and detection complexity. Simulation results show that the proposed algorithm can achieve better performance than cutting plane aided SDP method.展开更多
基金National Major Research and Development Program(2021YFB2800404)National Natural Science Foundation of China(U23B2047,62321166651,62305294,and 92150302)+2 种基金Natural Science Foundation of Zhejiang Province(LDT23F04012F05)Fundamental Research Funds for the Central Universitiesand The Leading Innovative and Entrepreneur Team Introduction Program of Zhejiang(2021R01001).
文摘High-capacity on-chip optical transmitters and receivers are crucial for data transmissions.Currently,advanced multiplexing technologies,including wavelength division multiplexing(WDM),mode-division multiplexing(MDM),and polarization-divisionmultiplexing(PDM)have been developed to greatly enhance the link capacity.In this paper,monolithically integrated silicon photonic transmitter and receiver with an ultra-high-capacity density of 37.0 Tbps/cm^(2) were proposed and demonstrated by introducing hybrid multiplexers and arrayed modulators/photodetectors.For the demonstrated transmitter/receiver chips,there are five wavelength channels and four mode channels with dual polarizations involved,while all these channels have low excess losses of 1 to 2 dB and low crosstalk less than−15 dB.Finally,all 20 channels are able to work with 50 Gbps on–off keying(OOK)signals per channel,achieving a total capacity of 1T-bps within an ultra-compact chip size of 0.032 cm^(2) for transmitters and 0.022 cm^(2) for receivers.
基金supported by the National Major Research and Development Program(Grant No.2019YFB2203600)the National Science Fund for Distinguished Young Scholars(Grant No.61725503)+3 种基金the National Natural Science Foundation of China(Grant Nos.62125503,91950205,61961146003,and 62005238)the Zhejiang Provincial Natural Science Foundation(Grant No.LD19F050001)The Fundamental Research Funds for the Central UniversitiesThe Leading Innovative and Entrepreneur Team Introduction Program of Zhejiang(Grant No.2021R01001).
文摘Dealing with the increase in data workloads and network complexity requires efficient selective manipulation of any channels in hybrid mode-/wavelength-division multiplexing(MDM/WDM)systems.A reconfigurable optical add-drop multiplexer(ROADM)using special modal field redistribution is proposed and demonstrated to enable the selective access of any mode-/wavelength-channels.With the assistance of the subwavelength grating structures,the launched modes are redistributed to be the supermodes localized at different regions of the multimode bus waveguide.Microring resonators are placed at the corresponding side of the bus waveguide to have specific evanescent coupling of the redistributed supermodes,so that any mode-/wavelength-channel can be added/dropped by thermally tuning the resonant wavelength.As an example,a ROADM for the case with three mode-channels is designed with low excess losses of<0.6,0.7,and 1.3 dB as well as low cross talks of<−26.3,−28.5,and−39.3 dB for the TE0,TE1,and TE2 modes,respectively,around the central wavelength of 1550 nm.The data transmission of 30 Gbps∕channel is also demonstrated successfully.The present ROADM provides a promising route for data switching/routing in hybrid MDM/WDM systems.
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supported by the National Natural Science Foundation of China(no.62275167,62405287,61905147,92250304)the Natural Science Foundation of Zhejiang Province(no.LZYQ25F050001)the Key R&D Program of Zhejiang(no.2024SSYS0014).
文摘Orbital angular momentum(OAM)beams,characterized by a helical phase structure and phase singularity,have emerged as a powerful resource for high-capacity optical communications through mode-division multiplexing(MDM).Traditional OAM multiplexing systems operating solely in the spatial domain face significant challenges,including increased system complexity,inter-modal crosstalk,and limited scalability.Recent advances have explored hybrid multiplexing schemes combining OAM with wavelength or polarization degrees of freedom,demonstrating Pbit/s level transmission capacities.However,these systems predominantly rely on continuous-wave lasers and external modulators,which constrain their applicability in challenging environments,whereas pulsed lasers provide superior peak power,enhanced transmission robustness,and the potential for implementation of OAM lasers,which generally emit pulsed OAM beams.Here,we report an OAM-based spatiotemporal multiplexing(OAM-STM)technique that synergistically implements pulsed OAM beams with a diffractive deep neural network(D^(2)NN)and optical fiber delay lines to project spatial mode information into the temporal domain.This approach leverages the full potential of pulsed laser sources by activating the underutilized time dimension,thereby overcoming the repetition-rate bottleneck and enhancing channel throughput.We experimentally demonstrate an OAM-based spatiotemporal demultiplexer achieving demultiplexing speed limited only by the bandwidth of the photodiode if OAM generation is fast enough.In the meantime,the architecture is intrinsically compatible with high-repetition-rate OAM sources,offering the entire system the scalability to GHz rates.This work establishes a foundational framework for high-speed,all-optical,and high-capacity OAM-STM systems,with promising implications for free-space optical communication,underwater communication links,and other complex environments.
文摘The aim of this study was to look in depth at the relationship between meiotic anomalies and male infertility, such as the determination of the chromosomes involved or the correlation with patient features. For this purpose, a total of 31 testicular tissue samples from individuals consulting for fertility problems were analyzed. Metaphase I cells were evaluated using a sequential methodology combining Leishman stained procedures and multiplex fluorescence in situ hybridization protocols. The number of chromosomal units and chiasmata count per bivalent were established and a hierarchical cluster analysis of the individuals was performed. The relationship of the seminogram and the karyotype over recombination were evaluated using Poisson regression models. Results obtained in this study show a significant percentage of infertile individuals with altered meiotic behavior, mostly specified as a reduction in chiasmata count in medium and large chromosomes, the presence of univalents, and the observation of tetraploid metaphases. Moreover, the number and the type of anomalies were found to be different between cells of the same individual, suggesting the coexistence of cell lines with normal meiotic behavior and cell lines with abnormalities. In addition, chromosomal abnormalities in metaphase I are significantly associated with oligozoospermia and/or polymorphic karyotype variants.
基金support from the Swiss National Science Foundation(SNSF)grant 310030_192757the Fundamental Research Funds for the Central Universities 13702150142the Shanghai Science and Technology Program Project 24ZR1468000.
文摘A critical gap currently exists in systematic understanding and experimental validation of the role of astrocytes in neurovascular coupling and their functional links with other brain cells.Despite a broad selection of functional neuroimaging tools for multi-scale brain interrogations,no methodology currently exists that can discern responses from neural and glial cells while simultaneously mapping the associated hemodynamic activity on a large scale.We present a hybrid multiplexed fluorescence and magnetic resonance imaging(HyFMRI)platform for measuring neuronal and astrocytic activity registered to concurrently recorded brain-wide hemodynamic responses.It features a fiberscope-based imaging system for multichannel fluorescence and optical intrinsic signal recordings and a custom surface radiofrequency coil,which are incorporated into the bore of a preclinical magnetic resonance imaging(MRI)scanner.We used HyFMRI to study peripheral-stimulus-evoked brain responses in mice differentially labeled with RCaMP and GCaMP genetically-encoded calcium indicators.Stimulation-evoked neuronal responses displayed the fastest kinetics and highest activation amplitude followed by astrocytic signals and the hemodynamic responses simultaneously recorded with functional MRI.In addition,the activation traces from neurons and astrocytes exhibited high linear correlation,thus providing direct evidence of astrocytic mediation in neurovascular coupling.This newly developed capacity to capture cell-type-specific calcium signaling alongside whole-brain hemodynamics enables the simultaneous investigation of neuro-glial-vascular interactions in health and disease.HyFMRI thus expands the current neuroimaging toolbox for a wide range of studies into synaptic plasticity,neural circuitry,brain function and disorders.
基金the National Natural Science Foundation of China (90604035)
文摘Non-orthogonal time-frequency division multiplexing （NTFDM） transmission scheme has been proposed to further improve the bandwidth efficiency and overcome the drawbacks of the conventional orthogonal frequency division multiplexing （OFDM） method. Based on such approach, the fast signal detection algorithm, semidefinite programming （SDP） detection, has been studied. As the coefficient matrix tends to be ill conditioned, the modified SDP algorithm combined with successive interference cancellation （SIC） has been developed. The improved algorithm is a good tradeoff between performance and detection complexity. Simulation results show that the proposed algorithm can achieve better performance than cutting plane aided SDP method.
