Weakly-coupled mode division multiplexing(MDM)technique is considered a promising candidate to enhance the capacity of an optical transmission system,in which mode multiplexers/demultiplexers(MMUX/MDEMUX)with low inse...Weakly-coupled mode division multiplexing(MDM)technique is considered a promising candidate to enhance the capacity of an optical transmission system,in which mode multiplexers/demultiplexers(MMUX/MDEMUX)with low insertion loss and modal crosstalk are the key components.In this paper,a low-modal-crosstalk 4-mode MMUX/MDEMUX for the weakly-coupled triple-ring-core few-mode fiber(TRC-FMF)is designed and fabricated with side-polishing processing.The measurement results show that a pair of MMUX/MDEMUX and 25 km weakly-coupled TRC-FMF MDM link achieve low modal crosstalk of lower than−17.5 dB and insertion loss of lower than 11.56 dB for all the four modes.Based on the TRC-FMF and all-fiber MMUX/MDEMUX,an experiment for 25 km real-time 4-mode 3-λwavelength division multiplexing(WDM)-MDM transmission is conducted using commercial 400G optical transport network(OTN)transceivers.The experimental results prove weakly-coupled MDM techniques facilitate a smooth upgrade of the optical transmission system.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
Femtosecond laser fabrication technology has been applied to photonic-lantern mode(de)multiplexers owing to its 3D fabrication capability.Current photonic-lantern mode(de)multiplexer designs based on femtosecond laser...Femtosecond laser fabrication technology has been applied to photonic-lantern mode(de)multiplexers owing to its 3D fabrication capability.Current photonic-lantern mode(de)multiplexer designs based on femtosecond laser fabrication technology mostly follow a fibre-type photonic lantern design,which uses trajectory-symmetry structures with non-uniform waveguides for selective mode excitation.However,non-uniform waveguides can lead to inconsistent waveguide transmission and coupling losses.Trajectory-symmetry designs are inefficient for selective-mode excitation.Therefore,we optimised the design using trajectory asymmetry with uniform waveguides and fabricated superior ultrafast laser-inscribed photonic-lantern mode(de)multiplexers.Consistent waveguide transmission and coupling losses(0.1 dB/cm and 0.2 dB/facet,respectively)at 1550 nm were obtained on uniform single-mode waveguides.Based on the trajectory-asymmetry design for photonic-lantern mode LPa11 LPb11 LP01(de)multiplexers,efficient mode excitation(,,and)with average insertion losses as low as 1 dB at 1550 nm was achieved,with mode-dependent losses of less than 0.3 dB.The photonic-lantern design was polarisation-insensitive,and the polarisation-determined losses were less than 0.2 dB.Along with polarisation LPa11x LPa11y LPb11x LPb11y LP01xmultiplexing realised by fibre-type polarisation beam splitters,six signal channels(,,,,,LP01yand),each carrying 42 Gaud/s quadrature phase-shift keying signals,were transmitted through a few-mode fibre for optical transmission.The average insertion loss of the system is less than 5 dB,while its maximum crosstalk with the few-mode fibre is less than-12 dB,leading to a 4-dB power penalty.The findings of this study pave the way for the practical application of 3D integrated photonic chips in high-capacity optical transmission systems.展开更多
We report on an eight-channel reconfigurable optical add-drop multiplexer based on cascaded microring resonators with a high tuning power consumption and a compact footprint. Microheaters are fabricated on top of the ...We report on an eight-channel reconfigurable optical add-drop multiplexer based on cascaded microring resonators with a high tuning power consumption and a compact footprint. Microheaters are fabricated on top of the microring resonators and can be modulated using the thermo-optic effect to achieve the reconfigurable functionality of the device. We demonstrate the reconfigurable add-drop multiplexing functionality for channel spacings of 1 O0 GHz and 50 GHz, with the centre wavelengths of the channels aligned to International Telecommunication Union grid specifications. The crosstalk for channel spacings of 100 GHz and 50 GHz are less than -22.5 dB and -15.5 dB, respectively. The average tuning efficiency is about 4.5 mW/nm, and the response speed is about 13.0 kHz.展开更多
A 16-channel arrayed waveguide grating(AWG)with an 800 GHz channel spacing in the O-band has been developed and fabricated based on silica planar lightwave circuit(PLC)technology.By extending the wave⁃length allocatio...A 16-channel arrayed waveguide grating(AWG)with an 800 GHz channel spacing in the O-band has been developed and fabricated based on silica planar lightwave circuit(PLC)technology.By extending the wave⁃length allocation from 8 channels to 16 channels as specified in IEEE 802.3bs,we increased the number of chan⁃nels and boosted transmission capacity to meet the 1.6 Tbps and higher-speed signal transmission requirements for future data centers.Through optimizing the AWG structure,it has achieved insertion loss(IL)better than-1.61 dB,loss uniformity below 0.35 dB,polarization-dependent loss(PDL)below 0.35 dB,adjacent channel cross⁃talk under-20.05 dB,ripple less than 0.75 dB,center wavelength offset under 0.22 nm and 1 dB bandwidth ex⁃ceeding 2.88 nm.The AWG has been successfully measured to transmit 53 Gbaud 4-level pulse amplitude modu⁃lation(PAM4)signal per channel and the total transmission speed can reach over 1.6 Tbps.展开更多
Introduction: Arbovirus diseases such as dengue and chikungunya threaten public health worldwide. Early and rapid diagnosis and surveillance of dengue virus (DENV) and chikungunya virus (CHIKV) infections are essentia...Introduction: Arbovirus diseases such as dengue and chikungunya threaten public health worldwide. Early and rapid diagnosis and surveillance of dengue virus (DENV) and chikungunya virus (CHIKV) infections are essential to the control of these diseases. In this study, we evaluate the diagnostic performance of our new in-house multiplex RT-qPCR method for detecting DENV serotypes and CHIKV in an external laboratory. Methodology: The evaluation study was conducted on 200 clinical samples of suspected patients for arbovirus disease infection, collected in Centre de Recherche Biomoléculaire Pietro Annigoni (CERBA), Ouagadougou, Burkina Faso. Our new multiplex RT-qPCR was compared to the commercial kit, the Zika, Dengue, and Chikungunya (ZDC) Real-Time PCR Assays kit (Bio-Rad, California, USA). Results and Conclusions: Among 200 samples, 21.5% (43/200) were DENV-positive by multiplex RT-qPCR, and 21.5% (43/200) were also DENV-positive by reference real-time RT-PCR. 157 (78.5%) samples tested negative for DENV by both tests (new mRT-qPCR and reference test). The sensitivity and specificity of mRT-qPCR were 100%. The DENV serotypes detected were DENV-1 60.5% (26/43) and DENV-3 39.5% (17/43). CHIKV was not detected in this study. Our new mRT-qPCR is sensitive, cost-effective, simple, and can be used in developing country laboratories.展开更多
Advancements in mode-division multiplexing(MDM)techniques,aimed at surpassing the Shannon limit and augmenting transmission capacity,have garnered significant attention in optical fiber communica-tion,propelling the d...Advancements in mode-division multiplexing(MDM)techniques,aimed at surpassing the Shannon limit and augmenting transmission capacity,have garnered significant attention in optical fiber communica-tion,propelling the demand for high-quality multiplexers and demultiplexers.However,the criteria for ideal-mode multiplexers/demultiplexers,such as performance,scalability,compatibility,and ultra-compactness,have only partially been achieved using conventional bulky devices(e.g.,waveguides,grat-ings,and free space optics)—an issue that will substantially restrict the application of MDM techniques.Here,we present a neuro-meta-router(NMR)optimized through deep learning that achieves spatial multi-mode division and supports multi-channel communication,potentially offering scalability,com-patibility,and ultra-compactness.An MDM communication system based on an NMR is theoretically designed and experimentally demonstrated to enable simultaneous and independent multi-dataset transmission,showcasing a capacity of up to 100 gigabits per second(Gbps)and a symbol error rate down to the order of 104,all achieved without any compensation technologies or correlation devices.Our work presents a paradigm that merges metasurfaces,fiber communications,and deep learning,with potential applications in intelligent metasurface-aided optical interconnection,as well as all-optical pat-tern recognition and classification.展开更多
Recent advancements in artificial intelligence have transformed three-dimensional(3D)optical imaging and metrology,enabling high-resolution and high-precision 3D surface geometry measurements from one single fringe pa...Recent advancements in artificial intelligence have transformed three-dimensional(3D)optical imaging and metrology,enabling high-resolution and high-precision 3D surface geometry measurements from one single fringe pattern projection.However,the imaging speed of conventional fringe projection profilometry(FPP)remains limited by the native sensor refresh rates due to the inherent"one-to-one"synchronization mechanism between pattern projection and image acquisition in standard structured light techniques.Here,we present dual-frequency angular-multiplexed fringe projection profilometry(DFAMFPP),a deep learning-enabled 3D imaging technique that achieves high-speed,high-precision,and large-depth-range absolute 3D surface measurements at speeds 16 times faster than the sensor's native frame rate.By encoding multi-timeframe 3D information into a single multiplexed image using multiple pairs of dual-frequency fringes,high-accuracy absolute phase maps are reconstructed using specially trained two-stage number-theoretical-based deep neural networks.We validate the effectiveness of DFAMFPP through dynamic scene measurements,achieving 10,000 Hz 3D imaging of a running turbofan engine prototype with only a 625 Hz camera.By overcoming the sensor hardware bottleneck,DFAMFPP significantly advances high-speed and ultra-high-speed 3D imaging,opening new avenues for exploring dynamic processes across diverse scientific disciplines.展开更多
Compact antenna designs have become a critical component in the recent advancements of wireless communication technologies over the past few decades. This paper presents a self-multiplexing antenna based on diplexing ...Compact antenna designs have become a critical component in the recent advancements of wireless communication technologies over the past few decades. This paper presents a self-multiplexing antenna based on diplexing and quadruplexing Substrate-Integrated Waveguide (SIW) cavities. The diplexing structure incorporates two V-shaped slots, while the quadruplexing structure advances this concept by combining the slots to form a cross-shaped configuration within the cavity. The widths and lengths of the slots are carefully tuned to achieve variations in the respective operating frequencies without affecting the others. The proposed diplexing antenna resonates at 8.48 and 9.2 GHz, with a frequency ratio of 1.08, while the quadruplexing antenna operates at 6.9, 7.1, 7.48, and 8.2GHz. Both designs exhibit isolation levels well below –20dB and achieve a simulated peak gain of 5.6 dBi at the highest frequency, with a compact cavity area of 0.56 λg^(2). The proposed antennas operate within the NR bands (n12, n18, n26), making them suitable for modern high-speed wireless communication systems. Moreover, the properties like multiband operation, compactness, high isolation, low loss, and low interference make the antenna favorable for the high-speed railway communication systems.展开更多
BACKGROUND Metabolic dysfunction-associated steatotic liver disease(MASLD),hepatic fibrosis,and cirrhosis are major risk factors for hepatocellular carcinoma(HCC),yet current blood-based diagnostic assays lack suffici...BACKGROUND Metabolic dysfunction-associated steatotic liver disease(MASLD),hepatic fibrosis,and cirrhosis are major risk factors for hepatocellular carcinoma(HCC),yet current blood-based diagnostic assays lack sufficient accuracy for routine clinical use.Identifying a non-invasive molecular signature that accurately detects liver disease could improve early diagnosis and monitoring.We hypothesized that the Liver FibraChek Dx■serum assay could discriminate MASLD and HCC from healthy controls using a multiplex biomarker-based algorithm.AIM To evaluate the diagnostic performance of the Liver FibraChek Dx■assay for detecting MASLD and HCC.METHODS This was a prospective,single-center study conducted in a United States tertiary care setting.Serum samples were collected from 45 participants(14 MASLD,19 HCC,12 healthy controls)with liver histology confirmed by biopsy.The Liver FibraChek Dx■algorithm integrates weighted values of aspartate aminotransferase,alanine aminotransferase,taurocholic acid,L-tyrosine,platelet count,and patient age to generate a risk score.Wilcoxon rank sum tests were used to assess associations with histologic diagnosis,and receiver operating characteristic(ROC)curves quantified diagnostic performance.RESULTS Liver FibraChek Dx■risk scores were significantly elevated in MASLD and HCC compared to controls(median:6.92±3.86 vs 3.61±1.67,P<0.001).The area under the ROC curve was 0.890(95%CI:0.776-1.000)for distinguishing diseased from healthy individuals.Sensitivity was 93.9%,specificity 75.0%,positive predictive value 91.1%,negative predictive value 81.8%,and overall accuracy 88.9%.CONCLUSION The Liver FibraChek Dx■assay accurately detects liver disease and shows promise as a non-invasive tool for diagnosing and monitoring MASLD and HCC.展开更多
In a few-mode erbium-doped fiber(FM-EDF),which is a key section in a space-division multiplexing(SDM)communication system,linearly polarized(LP)and orbital angular momentum(OAM)modes,as twomode bases with different ph...In a few-mode erbium-doped fiber(FM-EDF),which is a key section in a space-division multiplexing(SDM)communication system,linearly polarized(LP)and orbital angular momentum(OAM)modes,as twomode bases with different phase profiles,can be transformed into each other.In principle,the LP and OAM modes have a different mode spatial intensity distribution and a gain difference for FM-EDF amplifiers.How to analyze and characterize the differential mode-bases gain(DMBG)is important,but still an issue.We build,for the first time to our knowledge,a local analysis model composed of discrete elements of the FM-EDF cross section in areas of mode spatial intensity distribution azimuthal variation.Using the model of the two mode bases,analysis of local particle number distribution and detailed description of the local gain difference are realized,and the overall gain difference between the two mode bases is obtained.By building an amplifier system based on mode phase profile controlling,the gain of two mode bases is characterized experimentally.The measured DMBG is∼0.8 dB in the second-order mode,which is consistent with the simulation result.This result provides a potential way to reduce the mode gain difference in the FM-EDF,which is important in improving the performance of the SDM communication system.展开更多
Red-green-blue(RGB)beam combiners are widely used in scenarios such as augmented reality/virtual reality(AR/VR),laser projection,biochemical detection,and other fields.Optical waveguide combiners have attracted extens...Red-green-blue(RGB)beam combiners are widely used in scenarios such as augmented reality/virtual reality(AR/VR),laser projection,biochemical detection,and other fields.Optical waveguide combiners have attracted extensive attention due to their advantages of small size,high multiplexing efficiency,convenient mass production,and low cost.An RGB beam combiner based on directional couplers is designed,with a core-cladding relative refractive index difference of 0.75%.The RGB beam combiner is optimized from the perspective of parameter optimization.Using the beam propagation method(BPM),the relationship between the performance of the RGB beam combiner and individual parameters is studied,achieving preliminary optimization of the device’s performance.The key parameters of the RGB beam combiner are optimized using the entropy weight-technique for order preference by similarity to an ideal solution TOPSIS method,establishing the optimal parameter scheme and further improving the device’s performance indicators.The results show that after optimization,the multiplexing efficiencies for red,green,and blue lights,as well as the average multiplexing efficiency,reached 99.17%,99.76%,96.63%and 98.52%,respectively.The size of the RGB beam combiner is 4.768 mm×0.062 mm.展开更多
Channel state information(CSI)is very important to sparse code multiple access combined with orthogonal frequency division multiplexing(SCMA-OFDM)systems for data detection.The main goal of this paper is to tackle the...Channel state information(CSI)is very important to sparse code multiple access combined with orthogonal frequency division multiplexing(SCMA-OFDM)systems for data detection.The main goal of this paper is to tackle the computational complexity and pilot overhead issues when estima-ting and tracking the channel frequency response of each user in uplink SCMA-OFDM systems.To this end,a new binary pilot structure is first designed to realize the initial channel estimation with significantly reduced computational complexity.Then,a channel tracking method is proposed to update the channel estimation in time-varying channels,which exploits a modified least mean square(LMS)technique with the feedback from the detector.Simulation results show that the pro-posed pilot structure can provide accurate channel estimation results.Moreover,the average bit error rate(BER)performance of the modified LMS algorithm can approach that of a detector with perfect CSI within 2 dB at the normalized Doppler frequency up to 6×10^(-6).展开更多
In modern wireless communication and electromagnetic control,automatic modulationclassification(AMC)of orthogonal frequency division multiplexing(OFDM)signals plays animportant role.However,under Doppler frequency shi...In modern wireless communication and electromagnetic control,automatic modulationclassification(AMC)of orthogonal frequency division multiplexing(OFDM)signals plays animportant role.However,under Doppler frequency shift and complex multipath channel conditions,extracting discriminative features from high-order modulation signals and ensuring model inter-pretability remain challenging.To address these issues,this paper proposes a Fourier attention net-work(FAttNet),which combines an attention mechanism with a Fourier analysis network(FAN).Specifically,the method directly converts the input signal to the frequency domain using the FAN,thereby obtaining frequency features that reflect the periodic variations in amplitude and phase.Abuilt-in attention mechanism then automatically calculates the weights for each frequency band,focusing on the most discriminative components.This approach improves both classification accu-racy and model interpretability.Experimental validation was conducted via high-order modulationsimulation using an RF testbed.The results show that under three different Doppler frequencyshifts and complex multipath channel conditions,with a signal-to-noise ratio of 10 dB,the classifi-cation accuracy can reach 89.1%,90.4%and 90%,all of which are superior to the current main-stream methods.The proposed approach offers practical value for dynamic spectrum access and sig-nal security detection,and it makes important theoretical contributions to the application of deeplearning in complex electromagnetic signal recognition.展开更多
High peak-to-average power ratio(PAPR)is the main disadvantage of visible light communication-based orthogonal frequency division multiplexing(VLC-OFDM)systems.To address this problem,a novel precoding method is propo...High peak-to-average power ratio(PAPR)is the main disadvantage of visible light communication-based orthogonal frequency division multiplexing(VLC-OFDM)systems.To address this problem,a novel precoding method is proposed in this paper.The complex-valued precoding matrix is constructed by a Vandermonde matrix.The researched results show the proposed precoding scheme has better PAPR performance when compared to the conventional real-valued precoding methods.Moreover,a general closed-form expression of bit error rate(BER)for Vandermonde precoded VLC-OFDM is derived for multipath fading channel.The obtained BER formula shows that Vandermonde precoding can improve the BER performance of VLC-OFDM system over multipath fading channel.This is verified by the simulation results.The researched results also show that different precoding schemes have the same BER performance but different PAPR performance.展开更多
Adventitious agents,comprising unintentionally introduced microorganisms in the production of biological products,pose a significant challenge in ensuring the safety of gene therapy products.The revised International ...Adventitious agents,comprising unintentionally introduced microorganisms in the production of biological products,pose a significant challenge in ensuring the safety of gene therapy products.The revised International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use(ICH)guildline Q5A(R2)from September 2022 highlights the inclusion of viral vector-based gene therapy products in safety discussions,emphasizing controls in material sourcing,testing,and viral clearance[1].Detecting adventitious virus contamination is complex due to the unique characteristics of gene therapy products and the limitations of routine testing methods.The US Food and Drug Administration(FDA)recommends incorporating routine and specific virus detection methods,including those outlined in various pharmacopeias.Existing control methods have limitations,prompting the need for highly sensitive and broad-spectrum detection approaches.Unlike traditional biological products,gene therapy products primarily consist of live viruses,necessitating methods that distinguish between the main virus and adventitious viruses.Current virus detection techniques,such as polymerase chain reaction(PCR),sequencing,mass spectrometry,and DNA microarrays[2e4],have their drawbacks.展开更多
Multiple quantum well(MQW) Ⅲ-nitride diodes that can simultaneously emit and detect light feature an overlapping region between their electroluminescence and responsivity spectra, which allows them to be simultaneous...Multiple quantum well(MQW) Ⅲ-nitride diodes that can simultaneously emit and detect light feature an overlapping region between their electroluminescence and responsivity spectra, which allows them to be simultaneously used as both a transmitter and a receiver in a wireless light communication system. Here, we demonstrate a mobile light communication system using a time-division multiplexing(TDM) scheme to achieve bidirectional data transmission via the same optical channel.Two identical blue MQW diodes are defined by software as a transmitter or a receiver. To address the light alignment issue, an image identification module integrated with a gimbal stabilizer is used to automatically detect the locations of moving targets;thus, underwater audio communication is realized via a mobile blue-light TDM communication mode. This approach not only uses a single link but also integrates mobile nodes in a practical network.展开更多
Lanthanide(Ln^(3+))-doped luminescent nanocrystals(NCs)with excitation and emission in the second near-infrared biological window(NIRII,1000-1700 nm)have attracted considerable attention in the fields of deep-tissue b...Lanthanide(Ln^(3+))-doped luminescent nanocrystals(NCs)with excitation and emission in the second near-infrared biological window(NIRII,1000-1700 nm)have attracted considerable attention in the fields of deep-tissue bioimaging and non-invasive biodetection,owing to their superior advantages including good photochemical stability,sharp emission peaks,large penetration depth,and high signal-to-noise ratio[1].Conventionally,Yb3t-and Nd3t-sensitized NCs have been utilized as NIR-II luminescent nanoprobes for in vivo bioimaging upon excitation with 980 and 808 nm diode laser,respectively[2].展开更多
A novel suppression method of the phase noise is proposed to reduce the negative impacts of phase noise in coherent optical orthogonal frequency division multiplexing(CO-OFDM)systems.The method integrates the sub-symb...A novel suppression method of the phase noise is proposed to reduce the negative impacts of phase noise in coherent optical orthogonal frequency division multiplexing(CO-OFDM)systems.The method integrates the sub-symbol second-order polynomial interpolation(SSPI)with cubature Kalman filter(CKF)to improve the precision and effectiveness of the data processing through using a three-stage processing approach of phase noise.First of all,the phase noise values in OFDM symbols are calculated by using pilot symbols.Then,second-order Newton interpolation(SNI)is used in second-order interpolation to acquire precise noise estimation.Afterwards,every OFDM symbol is partitioned into several sub-symbols,and second-order polynomial interpolation(SPI)is utilized in the time domain to enhance suppression accuracy and time resolution.Ultimately,CKF is employed to suppress the residual phase noise.The simulation results show that this method significantly suppresses the impact of the phase noise on the system,and the error floors can be decreased at the condition of 16 quadrature amplitude modulation(16QAM)and 32QAM.The proposed method can greatly improve the CO-OFDM system's ability to tolerate the wider laser linewidth.This method,compared to the linear interpolation sub-symbol common phase error compensation(LI-SCPEC)and Lagrange interpolation and extended Kalman filter(LRI-EKF)algorithms,has superior suppression effect.展开更多
基金supported in part by the ZTE Industry-University-Institute Cooperation Funds.
文摘Weakly-coupled mode division multiplexing(MDM)technique is considered a promising candidate to enhance the capacity of an optical transmission system,in which mode multiplexers/demultiplexers(MMUX/MDEMUX)with low insertion loss and modal crosstalk are the key components.In this paper,a low-modal-crosstalk 4-mode MMUX/MDEMUX for the weakly-coupled triple-ring-core few-mode fiber(TRC-FMF)is designed and fabricated with side-polishing processing.The measurement results show that a pair of MMUX/MDEMUX and 25 km weakly-coupled TRC-FMF MDM link achieve low modal crosstalk of lower than−17.5 dB and insertion loss of lower than 11.56 dB for all the four modes.Based on the TRC-FMF and all-fiber MMUX/MDEMUX,an experiment for 25 km real-time 4-mode 3-λwavelength division multiplexing(WDM)-MDM transmission is conducted using commercial 400G optical transport network(OTN)transceivers.The experimental results prove weakly-coupled MDM techniques facilitate a smooth upgrade of the optical transmission system.
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supported by the National Natural Science Foundation of China(NSFC)(62125503,62261160388)the Natural Science Foundation of Hubei Province of China(2023AFA028)the Innovation Project of Optics Valley Laboratory(OVL2021BG004).
文摘Femtosecond laser fabrication technology has been applied to photonic-lantern mode(de)multiplexers owing to its 3D fabrication capability.Current photonic-lantern mode(de)multiplexer designs based on femtosecond laser fabrication technology mostly follow a fibre-type photonic lantern design,which uses trajectory-symmetry structures with non-uniform waveguides for selective mode excitation.However,non-uniform waveguides can lead to inconsistent waveguide transmission and coupling losses.Trajectory-symmetry designs are inefficient for selective-mode excitation.Therefore,we optimised the design using trajectory asymmetry with uniform waveguides and fabricated superior ultrafast laser-inscribed photonic-lantern mode(de)multiplexers.Consistent waveguide transmission and coupling losses(0.1 dB/cm and 0.2 dB/facet,respectively)at 1550 nm were obtained on uniform single-mode waveguides.Based on the trajectory-asymmetry design for photonic-lantern mode LPa11 LPb11 LP01(de)multiplexers,efficient mode excitation(,,and)with average insertion losses as low as 1 dB at 1550 nm was achieved,with mode-dependent losses of less than 0.3 dB.The photonic-lantern design was polarisation-insensitive,and the polarisation-determined losses were less than 0.2 dB.Along with polarisation LPa11x LPa11y LPb11x LPb11y LP01xmultiplexing realised by fibre-type polarisation beam splitters,six signal channels(,,,,,LP01yand),each carrying 42 Gaud/s quadrature phase-shift keying signals,were transmitted through a few-mode fibre for optical transmission.The average insertion loss of the system is less than 5 dB,while its maximum crosstalk with the few-mode fibre is less than-12 dB,leading to a 4-dB power penalty.The findings of this study pave the way for the practical application of 3D integrated photonic chips in high-capacity optical transmission systems.
文摘We report on an eight-channel reconfigurable optical add-drop multiplexer based on cascaded microring resonators with a high tuning power consumption and a compact footprint. Microheaters are fabricated on top of the microring resonators and can be modulated using the thermo-optic effect to achieve the reconfigurable functionality of the device. We demonstrate the reconfigurable add-drop multiplexing functionality for channel spacings of 1 O0 GHz and 50 GHz, with the centre wavelengths of the channels aligned to International Telecommunication Union grid specifications. The crosstalk for channel spacings of 100 GHz and 50 GHz are less than -22.5 dB and -15.5 dB, respectively. The average tuning efficiency is about 4.5 mW/nm, and the response speed is about 13.0 kHz.
基金Supported by the National Key Research and Development Program of China(2021YFB2800201)the Strategic Priority Research Program of Chinese Academy of Sciences(XDB43000000)。
文摘A 16-channel arrayed waveguide grating(AWG)with an 800 GHz channel spacing in the O-band has been developed and fabricated based on silica planar lightwave circuit(PLC)technology.By extending the wave⁃length allocation from 8 channels to 16 channels as specified in IEEE 802.3bs,we increased the number of chan⁃nels and boosted transmission capacity to meet the 1.6 Tbps and higher-speed signal transmission requirements for future data centers.Through optimizing the AWG structure,it has achieved insertion loss(IL)better than-1.61 dB,loss uniformity below 0.35 dB,polarization-dependent loss(PDL)below 0.35 dB,adjacent channel cross⁃talk under-20.05 dB,ripple less than 0.75 dB,center wavelength offset under 0.22 nm and 1 dB bandwidth ex⁃ceeding 2.88 nm.The AWG has been successfully measured to transmit 53 Gbaud 4-level pulse amplitude modu⁃lation(PAM4)signal per channel and the total transmission speed can reach over 1.6 Tbps.
文摘Introduction: Arbovirus diseases such as dengue and chikungunya threaten public health worldwide. Early and rapid diagnosis and surveillance of dengue virus (DENV) and chikungunya virus (CHIKV) infections are essential to the control of these diseases. In this study, we evaluate the diagnostic performance of our new in-house multiplex RT-qPCR method for detecting DENV serotypes and CHIKV in an external laboratory. Methodology: The evaluation study was conducted on 200 clinical samples of suspected patients for arbovirus disease infection, collected in Centre de Recherche Biomoléculaire Pietro Annigoni (CERBA), Ouagadougou, Burkina Faso. Our new multiplex RT-qPCR was compared to the commercial kit, the Zika, Dengue, and Chikungunya (ZDC) Real-Time PCR Assays kit (Bio-Rad, California, USA). Results and Conclusions: Among 200 samples, 21.5% (43/200) were DENV-positive by multiplex RT-qPCR, and 21.5% (43/200) were also DENV-positive by reference real-time RT-PCR. 157 (78.5%) samples tested negative for DENV by both tests (new mRT-qPCR and reference test). The sensitivity and specificity of mRT-qPCR were 100%. The DENV serotypes detected were DENV-1 60.5% (26/43) and DENV-3 39.5% (17/43). CHIKV was not detected in this study. Our new mRT-qPCR is sensitive, cost-effective, simple, and can be used in developing country laboratories.
基金supported by the National Key Research and Development Program of China(2023YFB2804704)the National Natural Science Foundation of China(12174292,12374278,and 62105250).
文摘Advancements in mode-division multiplexing(MDM)techniques,aimed at surpassing the Shannon limit and augmenting transmission capacity,have garnered significant attention in optical fiber communica-tion,propelling the demand for high-quality multiplexers and demultiplexers.However,the criteria for ideal-mode multiplexers/demultiplexers,such as performance,scalability,compatibility,and ultra-compactness,have only partially been achieved using conventional bulky devices(e.g.,waveguides,grat-ings,and free space optics)—an issue that will substantially restrict the application of MDM techniques.Here,we present a neuro-meta-router(NMR)optimized through deep learning that achieves spatial multi-mode division and supports multi-channel communication,potentially offering scalability,com-patibility,and ultra-compactness.An MDM communication system based on an NMR is theoretically designed and experimentally demonstrated to enable simultaneous and independent multi-dataset transmission,showcasing a capacity of up to 100 gigabits per second(Gbps)and a symbol error rate down to the order of 104,all achieved without any compensation technologies or correlation devices.Our work presents a paradigm that merges metasurfaces,fiber communications,and deep learning,with potential applications in intelligent metasurface-aided optical interconnection,as well as all-optical pat-tern recognition and classification.
基金supported by National Key Research and Development Program of China(2022YFB2804603,2022YFB2804605)National Natural Science Foundation of China(U21B2033)+4 种基金Fundamental Research Funds forthe Central Universities(2023102001,2024202002)National Key Laborato-ry of Shock Wave and Detonation Physics(JCKYS2024212111)China Post-doctoral Science Fund(2023T160318)Open Research Fund of JiangsuKey Laboratory of Spectral Imaging&Intelligent Sense(JSGP202105,JSGP202201)Postgraduate Research&Practice Innovation Program of Jiangsu Province(KYCX25_0695,SJCX25_0188)。
文摘Recent advancements in artificial intelligence have transformed three-dimensional(3D)optical imaging and metrology,enabling high-resolution and high-precision 3D surface geometry measurements from one single fringe pattern projection.However,the imaging speed of conventional fringe projection profilometry(FPP)remains limited by the native sensor refresh rates due to the inherent"one-to-one"synchronization mechanism between pattern projection and image acquisition in standard structured light techniques.Here,we present dual-frequency angular-multiplexed fringe projection profilometry(DFAMFPP),a deep learning-enabled 3D imaging technique that achieves high-speed,high-precision,and large-depth-range absolute 3D surface measurements at speeds 16 times faster than the sensor's native frame rate.By encoding multi-timeframe 3D information into a single multiplexed image using multiple pairs of dual-frequency fringes,high-accuracy absolute phase maps are reconstructed using specially trained two-stage number-theoretical-based deep neural networks.We validate the effectiveness of DFAMFPP through dynamic scene measurements,achieving 10,000 Hz 3D imaging of a running turbofan engine prototype with only a 625 Hz camera.By overcoming the sensor hardware bottleneck,DFAMFPP significantly advances high-speed and ultra-high-speed 3D imaging,opening new avenues for exploring dynamic processes across diverse scientific disciplines.
文摘Compact antenna designs have become a critical component in the recent advancements of wireless communication technologies over the past few decades. This paper presents a self-multiplexing antenna based on diplexing and quadruplexing Substrate-Integrated Waveguide (SIW) cavities. The diplexing structure incorporates two V-shaped slots, while the quadruplexing structure advances this concept by combining the slots to form a cross-shaped configuration within the cavity. The widths and lengths of the slots are carefully tuned to achieve variations in the respective operating frequencies without affecting the others. The proposed diplexing antenna resonates at 8.48 and 9.2 GHz, with a frequency ratio of 1.08, while the quadruplexing antenna operates at 6.9, 7.1, 7.48, and 8.2GHz. Both designs exhibit isolation levels well below –20dB and achieve a simulated peak gain of 5.6 dBi at the highest frequency, with a compact cavity area of 0.56 λg^(2). The proposed antennas operate within the NR bands (n12, n18, n26), making them suitable for modern high-speed wireless communication systems. Moreover, the properties like multiband operation, compactness, high isolation, low loss, and low interference make the antenna favorable for the high-speed railway communication systems.
文摘BACKGROUND Metabolic dysfunction-associated steatotic liver disease(MASLD),hepatic fibrosis,and cirrhosis are major risk factors for hepatocellular carcinoma(HCC),yet current blood-based diagnostic assays lack sufficient accuracy for routine clinical use.Identifying a non-invasive molecular signature that accurately detects liver disease could improve early diagnosis and monitoring.We hypothesized that the Liver FibraChek Dx■serum assay could discriminate MASLD and HCC from healthy controls using a multiplex biomarker-based algorithm.AIM To evaluate the diagnostic performance of the Liver FibraChek Dx■assay for detecting MASLD and HCC.METHODS This was a prospective,single-center study conducted in a United States tertiary care setting.Serum samples were collected from 45 participants(14 MASLD,19 HCC,12 healthy controls)with liver histology confirmed by biopsy.The Liver FibraChek Dx■algorithm integrates weighted values of aspartate aminotransferase,alanine aminotransferase,taurocholic acid,L-tyrosine,platelet count,and patient age to generate a risk score.Wilcoxon rank sum tests were used to assess associations with histologic diagnosis,and receiver operating characteristic(ROC)curves quantified diagnostic performance.RESULTS Liver FibraChek Dx■risk scores were significantly elevated in MASLD and HCC compared to controls(median:6.92±3.86 vs 3.61±1.67,P<0.001).The area under the ROC curve was 0.890(95%CI:0.776-1.000)for distinguishing diseased from healthy individuals.Sensitivity was 93.9%,specificity 75.0%,positive predictive value 91.1%,negative predictive value 81.8%,and overall accuracy 88.9%.CONCLUSION The Liver FibraChek Dx■assay accurately detects liver disease and shows promise as a non-invasive tool for diagnosing and monitoring MASLD and HCC.
基金supported by the National Key Research and Development Program of China(Grant No.2019YFA0706300)the National Natural Science Foundation of China(Grant Nos.U22B2010,62035018,and U2001601)+1 种基金the Program of Marine Economy Development Special Fund(Six Marine Industries)under the Department of Natural Resources of Guangdong Province(Grant No.GDNRC[2024]16)the project supported by the Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai)(Grant No.SML2023SP231).
文摘In a few-mode erbium-doped fiber(FM-EDF),which is a key section in a space-division multiplexing(SDM)communication system,linearly polarized(LP)and orbital angular momentum(OAM)modes,as twomode bases with different phase profiles,can be transformed into each other.In principle,the LP and OAM modes have a different mode spatial intensity distribution and a gain difference for FM-EDF amplifiers.How to analyze and characterize the differential mode-bases gain(DMBG)is important,but still an issue.We build,for the first time to our knowledge,a local analysis model composed of discrete elements of the FM-EDF cross section in areas of mode spatial intensity distribution azimuthal variation.Using the model of the two mode bases,analysis of local particle number distribution and detailed description of the local gain difference are realized,and the overall gain difference between the two mode bases is obtained.By building an amplifier system based on mode phase profile controlling,the gain of two mode bases is characterized experimentally.The measured DMBG is∼0.8 dB in the second-order mode,which is consistent with the simulation result.This result provides a potential way to reduce the mode gain difference in the FM-EDF,which is important in improving the performance of the SDM communication system.
基金Project(52175445)supported by the National Natural Science Foundation of ChinaProject(2022JJ30743)supported by the Natural Science Foundation of Hunan Province,China+1 种基金Project(2023GK2024)supported by the Key Research and Development Program of Hunan Province,ChinaProject(2023ZZTS0391)supported by the Fundamental Research Funds for the Central Universities of China。
文摘Red-green-blue(RGB)beam combiners are widely used in scenarios such as augmented reality/virtual reality(AR/VR),laser projection,biochemical detection,and other fields.Optical waveguide combiners have attracted extensive attention due to their advantages of small size,high multiplexing efficiency,convenient mass production,and low cost.An RGB beam combiner based on directional couplers is designed,with a core-cladding relative refractive index difference of 0.75%.The RGB beam combiner is optimized from the perspective of parameter optimization.Using the beam propagation method(BPM),the relationship between the performance of the RGB beam combiner and individual parameters is studied,achieving preliminary optimization of the device’s performance.The key parameters of the RGB beam combiner are optimized using the entropy weight-technique for order preference by similarity to an ideal solution TOPSIS method,establishing the optimal parameter scheme and further improving the device’s performance indicators.The results show that after optimization,the multiplexing efficiencies for red,green,and blue lights,as well as the average multiplexing efficiency,reached 99.17%,99.76%,96.63%and 98.52%,respectively.The size of the RGB beam combiner is 4.768 mm×0.062 mm.
基金Supported by the National Natural Science Foundation of China(No.62171135)the Natural Science Foundation of Fujian Province(No.2023J01399)。
文摘Channel state information(CSI)is very important to sparse code multiple access combined with orthogonal frequency division multiplexing(SCMA-OFDM)systems for data detection.The main goal of this paper is to tackle the computational complexity and pilot overhead issues when estima-ting and tracking the channel frequency response of each user in uplink SCMA-OFDM systems.To this end,a new binary pilot structure is first designed to realize the initial channel estimation with significantly reduced computational complexity.Then,a channel tracking method is proposed to update the channel estimation in time-varying channels,which exploits a modified least mean square(LMS)technique with the feedback from the detector.Simulation results show that the pro-posed pilot structure can provide accurate channel estimation results.Moreover,the average bit error rate(BER)performance of the modified LMS algorithm can approach that of a detector with perfect CSI within 2 dB at the normalized Doppler frequency up to 6×10^(-6).
基金supported by the National Natural Science Foundation of China(No.62027801).
文摘In modern wireless communication and electromagnetic control,automatic modulationclassification(AMC)of orthogonal frequency division multiplexing(OFDM)signals plays animportant role.However,under Doppler frequency shift and complex multipath channel conditions,extracting discriminative features from high-order modulation signals and ensuring model inter-pretability remain challenging.To address these issues,this paper proposes a Fourier attention net-work(FAttNet),which combines an attention mechanism with a Fourier analysis network(FAN).Specifically,the method directly converts the input signal to the frequency domain using the FAN,thereby obtaining frequency features that reflect the periodic variations in amplitude and phase.Abuilt-in attention mechanism then automatically calculates the weights for each frequency band,focusing on the most discriminative components.This approach improves both classification accu-racy and model interpretability.Experimental validation was conducted via high-order modulationsimulation using an RF testbed.The results show that under three different Doppler frequencyshifts and complex multipath channel conditions,with a signal-to-noise ratio of 10 dB,the classifi-cation accuracy can reach 89.1%,90.4%and 90%,all of which are superior to the current main-stream methods.The proposed approach offers practical value for dynamic spectrum access and sig-nal security detection,and it makes important theoretical contributions to the application of deeplearning in complex electromagnetic signal recognition.
基金supported by the Zhejiang Provincial Natural Science Foundation of China(No.LZ21F010001)the Natural Science Foundation of Zhejiang University of Science and Technology(No.2023QN095)。
文摘High peak-to-average power ratio(PAPR)is the main disadvantage of visible light communication-based orthogonal frequency division multiplexing(VLC-OFDM)systems.To address this problem,a novel precoding method is proposed in this paper.The complex-valued precoding matrix is constructed by a Vandermonde matrix.The researched results show the proposed precoding scheme has better PAPR performance when compared to the conventional real-valued precoding methods.Moreover,a general closed-form expression of bit error rate(BER)for Vandermonde precoded VLC-OFDM is derived for multipath fading channel.The obtained BER formula shows that Vandermonde precoding can improve the BER performance of VLC-OFDM system over multipath fading channel.This is verified by the simulation results.The researched results also show that different precoding schemes have the same BER performance but different PAPR performance.
基金financially supported by Beijing Municipal Science&Technology Commission,China(Grant No.:Z221100007922015)Youth Development Research Foundation of National Institutes for Food and Drug Control,China(Grant No.:2020B1).
文摘Adventitious agents,comprising unintentionally introduced microorganisms in the production of biological products,pose a significant challenge in ensuring the safety of gene therapy products.The revised International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use(ICH)guildline Q5A(R2)from September 2022 highlights the inclusion of viral vector-based gene therapy products in safety discussions,emphasizing controls in material sourcing,testing,and viral clearance[1].Detecting adventitious virus contamination is complex due to the unique characteristics of gene therapy products and the limitations of routine testing methods.The US Food and Drug Administration(FDA)recommends incorporating routine and specific virus detection methods,including those outlined in various pharmacopeias.Existing control methods have limitations,prompting the need for highly sensitive and broad-spectrum detection approaches.Unlike traditional biological products,gene therapy products primarily consist of live viruses,necessitating methods that distinguish between the main virus and adventitious viruses.Current virus detection techniques,such as polymerase chain reaction(PCR),sequencing,mass spectrometry,and DNA microarrays[2e4],have their drawbacks.
基金jointly supported by the National Natural Science Foundation of China (U21A20495)Natural Science Foundation of Jiangsu Province (BG2024023)+1 种基金National Key Research and Development Program of China (2022YFE0112000)111 Project (D17018)。
文摘Multiple quantum well(MQW) Ⅲ-nitride diodes that can simultaneously emit and detect light feature an overlapping region between their electroluminescence and responsivity spectra, which allows them to be simultaneously used as both a transmitter and a receiver in a wireless light communication system. Here, we demonstrate a mobile light communication system using a time-division multiplexing(TDM) scheme to achieve bidirectional data transmission via the same optical channel.Two identical blue MQW diodes are defined by software as a transmitter or a receiver. To address the light alignment issue, an image identification module integrated with a gimbal stabilizer is used to automatically detect the locations of moving targets;thus, underwater audio communication is realized via a mobile blue-light TDM communication mode. This approach not only uses a single link but also integrates mobile nodes in a practical network.
基金supported by the National Natural Science Foundation of China(Nos.12474418,U22A20398,and 22135008).
文摘Lanthanide(Ln^(3+))-doped luminescent nanocrystals(NCs)with excitation and emission in the second near-infrared biological window(NIRII,1000-1700 nm)have attracted considerable attention in the fields of deep-tissue bioimaging and non-invasive biodetection,owing to their superior advantages including good photochemical stability,sharp emission peaks,large penetration depth,and high signal-to-noise ratio[1].Conventionally,Yb3t-and Nd3t-sensitized NCs have been utilized as NIR-II luminescent nanoprobes for in vivo bioimaging upon excitation with 980 and 808 nm diode laser,respectively[2].
基金supported by the National Natural Science Foundation of China(Nos.U21A20447 and 61971079)。
文摘A novel suppression method of the phase noise is proposed to reduce the negative impacts of phase noise in coherent optical orthogonal frequency division multiplexing(CO-OFDM)systems.The method integrates the sub-symbol second-order polynomial interpolation(SSPI)with cubature Kalman filter(CKF)to improve the precision and effectiveness of the data processing through using a three-stage processing approach of phase noise.First of all,the phase noise values in OFDM symbols are calculated by using pilot symbols.Then,second-order Newton interpolation(SNI)is used in second-order interpolation to acquire precise noise estimation.Afterwards,every OFDM symbol is partitioned into several sub-symbols,and second-order polynomial interpolation(SPI)is utilized in the time domain to enhance suppression accuracy and time resolution.Ultimately,CKF is employed to suppress the residual phase noise.The simulation results show that this method significantly suppresses the impact of the phase noise on the system,and the error floors can be decreased at the condition of 16 quadrature amplitude modulation(16QAM)and 32QAM.The proposed method can greatly improve the CO-OFDM system's ability to tolerate the wider laser linewidth.This method,compared to the linear interpolation sub-symbol common phase error compensation(LI-SCPEC)and Lagrange interpolation and extended Kalman filter(LRI-EKF)algorithms,has superior suppression effect.
