With the development of wireless communication,the 6G mobile communication technology has received wide attention.As one of the key technologies of 6G,terahertz(THz)communication technology has the characteristics of ...With the development of wireless communication,the 6G mobile communication technology has received wide attention.As one of the key technologies of 6G,terahertz(THz)communication technology has the characteristics of ultra-high bandwidth,high security and low environmental noise.In this paper,a THz duplexer with a half-wavelength coupling structure and a sub-harmonic mixer operating at 216 GHz and 204 GHz are designed and measured.Based on these key devices,a 220 GHz frequency-division multiplexing communication system is proposed,with a real-time data rate of 10.4 Gbit/s for one channel and a transmission distance of 15 m.The measured constellation diagram of two receivers is clearly visible,the signal-to-noise ratio(SNR)is higher than 22 dB,and the bit error ratio(BER)is less than 10^(−8).Furthermore,the high definition(HD)4K video can also be transmitted in real time without stutter.展开更多
This paper introduces a joint nonlinearity and chromatic dispersion pre-compensation method for coherent optical orthogonal frequency-division multiplexing systems. The research results show that this method can reduc...This paper introduces a joint nonlinearity and chromatic dispersion pre-compensation method for coherent optical orthogonal frequency-division multiplexing systems. The research results show that this method can reduce the walk- off effect and can therefore equalize the nonlinear impairments effectively. Compared with the only other existing nonlinearity pre-compensation method, the joint nonlinearity and chromatic dispersion pre-compensation method is not only suitable for low-dispersion optical orthogonal frequency-division multiplexing system, but also effective for high- dispersion optical orthogonal frequency-division multiplexing transmission system with higher input power but without optical dispersion compensation. The suggested solution does not increase computation complexity compared with only nonlinearity pre-compensation method. For 40 Gbit/s coherent optical orthogonal frequency-division multiplexing 20 × 80 km standard single-mode fibre system, the suggested method can improve the nonlinear threshold （for Q 〉 10 dB） about 2.7, 1.2 and 1.0 dB, and the maximum Q factor about 1.2, 0.4 and 0.3 dB, for 2, 8 and 16 ps/（nm.km） dispersion coefficients.展开更多
This paper presents a novel spec- trum sharing design aiming at optimising the performance of a Multiuser Orthogonal Freq- uency-Division Multiplexing （MU-OFDM） Co- gnitive Radio Network （CRN） that consists of mul...This paper presents a novel spec- trum sharing design aiming at optimising the performance of a Multiuser Orthogonal Freq- uency-Division Multiplexing （MU-OFDM） Co- gnitive Radio Network （CRN） that consists of multiple secondary Transmitter-Receiver （Tx-Rx） pairs. For most MU-OFDM systems, the Exc- lusive Subchannel Assignment （ESA） is an efficient resource allocation method. Noneth- eless, it is inappropriate for the network consi- dered in this paper, because subchannels shar- ing among secondary Tx-Rx pairs can further improve the system performance. We investi- gate the Weighted Sum Rate （WSR） maximi- zation problem under the Shared Subchannel Assignment （SSA）, where each subchannel is shared by multiple secondary Tx-Rx pairs. With Lagrangian duality technique, we decompose the original resource allocation problem into sev- eral sub-problems on each subchannel and pro- pose a duality-based suhchannel sharing ap- proach. For practical realisation in the cogni- tive systems without central control entity, a distributed duality-based WSR maximization scheme is presented. Simulation results mani- fest that the proposed scheme achieves sig- nificantly better performance than ESA duality scheme.展开更多
An optical frequency comb(OFC)frequency-division multiplexing dispersive interference multichannel distance measurement method is proposed.Based on the OFC dispersive interference,the wide OFC spectrum is divided into...An optical frequency comb(OFC)frequency-division multiplexing dispersive interference multichannel distance measurement method is proposed.Based on the OFC dispersive interference,the wide OFC spectrum is divided into multiple channels using a wavelength-division multiplexer.Under the existing light source and spectrometer,a single interference system can realize six channels of the high-precision parallel absolute distance measurement.The influence of the spectrum width and shape on the performance of the distance measurement channel is analyzed.The ranging accuracy of six channels is higher than±4μm under the optimization of a nonuniform discrete Fourier transform and Hanning window.展开更多
The rapidly growing global data usage has demanded more efficient ways to utilize the scarce electromagnetic spectrum resource. Recent research has focused on the development of efficient multiplexing techniques in th...The rapidly growing global data usage has demanded more efficient ways to utilize the scarce electromagnetic spectrum resource. Recent research has focused on the development of efficient multiplexing techniques in the millimeter-wave band(1-10 mm, or 30-300 GHz) due to the promise of large available bandwidth for future wireless networks. Frequency-division multiplexing is still one of the most commonly-used techniques to maximize the transmission capacity of a wireless network.Based on the frequency-selective tunnelling effect of the low-loss epsilon-near-zero metamaterial waveguide, we numerically and experimentally demonstrate five-channel frequency-division multiplexing and demultiplexing in the millimeter-wave range.We show that this device architecture offers great flexibility to manipulate the filter Q-factors and the transmission spectra of different channels, by changing of the epsilon-near-zero metamaterial waveguide topology and by adding a standard waveguide between two epsilon-near-zero channels. This strategy of frequency-division multiplexing may pave a way for efficiently allocating the spectrum for future communication networks.展开更多
Orthogonal frequency-division multiplexing （OFDM） systems are sensitive to carrier frequency offset （CFO） which introduces intercarder interference and significantly degrades system performance. This paper describ...Orthogonal frequency-division multiplexing （OFDM） systems are sensitive to carrier frequency offset （CFO） which introduces intercarder interference and significantly degrades system performance. This paper describes an iterative blind receiver consisting of a sequential Monte Carlo detector, a CFO estimator, and a compensator to reduce intercarrier interference. The framework is of low complexity due to the separation of tasks in a joint detection problem. In addition, the CFO estimator utilizes soft output of the sequential Monte Carlo detector, which reduces the information loss caused by hard decisions and can obtain the CFO estimate in only one OFDM symbol. Simulation results demonstrate the effectiveness of the algorithm.展开更多
We propose a two-cascaded, constant-resistance, symmetrical bridged-T amplitude equalizer for a high-speed visible light communication（VLC） system. With the pre-equalization circuit, the-3 d B bandwidth of the VLC s...We propose a two-cascaded, constant-resistance, symmetrical bridged-T amplitude equalizer for a high-speed visible light communication（VLC） system. With the pre-equalization circuit, the-3 d B bandwidth of the VLC system can be extended from 12 to 235 MHz using a commercially available phosphorescent white light-emitting diode（LED）, a blue filter, and a low-cost PIN photodiode. The data rate is 1.20 Gbit/s, exploiting 16-quadrature amplitude modulation-orthogonal frequency-division multiplexing with a 300 MHz modulation bandwidth over50 cm of free-space transmission under the pre-forward error correction limit of 3.8 × 10^-3. To our knowledge,this is the highest-3 d B bandwidth and the highest data rate ever achieved by using a pre-equalization circuit and white LED in a VLC system.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
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
Dynamically tunable terahertz(THz)beam focusing plays a critical role in emerging applications including reconfigurable imaging,localized spectral analysis,and micro-machining.Conventional methods,however,frequently e...Dynamically tunable terahertz(THz)beam focusing plays a critical role in emerging applications including reconfigurable imaging,localized spectral analysis,and micro-machining.Conventional methods,however,frequently employ complex wavefront modulators and external control algorithms,resulting in increased system footprint and limited tuning efficiency.In this work,we present an all-silicon mechanically rotatable cascaded metasurface capable of dynamic THz beam focusing.By independently adjusting the relative rotation angles between the two metasurface layers,real-time repositioning of the focal spot is achieved for orthogonal circular polarization channels.The proposed design facilitates polarization-division multiplexing without requiring external algorithms or active materials while preserving high focusing efficiency and beam quality across a predefined focal plane.Numerical simulations reveal a quasi-linear shift of the focal position with the rotation angle,with stable focusing efficiency and full-width at half-maximum observed in both polarization channels.This strategy offers an efficient and reliable approach to dynamic wavefront control for compact,reconfigurable THz imaging,sensing,and communication systems.展开更多
The exponential growth in data traffic has driven significant research into maximizing the capacity of free-space optical(FSO)communication systems.Orbital angular momentum(OAM)multiplexing offers a promising approach...The exponential growth in data traffic has driven significant research into maximizing the capacity of free-space optical(FSO)communication systems.Orbital angular momentum(OAM)multiplexing offers a promising approach by using spatially structured beams with helical wavefronts to achieve higher data transmission rates.However,conventional electronic convolutional-neural-network-based OAM demultiplexing schemes exhibit substantial computational and energy efficiency limitations.展开更多
In this work,a reflective metasurface connector(RMC)and its application for high-density and wideband spacedivision multiplexing(SDM)are demonstrated.This device features single facet metasurface fabrication over an S...In this work,a reflective metasurface connector(RMC)and its application for high-density and wideband spacedivision multiplexing(SDM)are demonstrated.This device features single facet metasurface fabrication over an SOI platform based on a CMOS compatible process.A minimum fiber-to-fiber insertion loss of 2.9 dB at 1598.24 nm is realized for fan-in-fan-out(FIFO)applications between a single-mode fiber(SMF)array and a multicore fiber(MCF).展开更多
The implementation of multiple pathogen testing is essential for a rapid response to future outbreaks and for reducing disease transmission.This study introduces a 96-channel microfluidic chip,fabricated through a mol...The implementation of multiple pathogen testing is essential for a rapid response to future outbreaks and for reducing disease transmission.This study introduces a 96-channel microfluidic chip,fabricated through a molding process,which enables the batch detection of pathogens.It explores the rapid lysis and elution processes of pathogens within the microfluidic chips to ensure that nucleic acid extraction,elution,and amplification are completed entirely within the chip.This chip can extract nucleic acids from samples in just 10 min,achieving an extraction efficiency comparable to that of traditional in-tube methods.An oil phase is pre-loaded into the chip to effectively prevent aerosol contamination.This approach allows for the simultaneous detection of 21 common respiratory pathogens,with a detection limit of 10 copies per reaction.Furthermore,applications involving clinical samples demonstrate significant practicality.Compared to many traditional in-tube pathogen detection methods and molecular biology technologies that utilize microfluidic chips,this detection chip not only enables simultaneous detection of multiple pathogens but also demonstrates high sensitivity.展开更多
Rice, a global staple food, is critical for food security. The cultivated Oryza sativa, domesticated from wild O. rufipogon, derives~80%of its 993 identified domestication-related genes from O. rufipogon and 20%from S...Rice, a global staple food, is critical for food security. The cultivated Oryza sativa, domesticated from wild O. rufipogon, derives~80%of its 993 identified domestication-related genes from O. rufipogon and 20%from South/Southeast Asian wild O. nivara(Jing et al., 2023). Genes like An-1, BH4, PROG1,SH4, Rc, Rd, and GS3—which regulate awn length, hull color,til er angle, seed shattering, pericarp color, seed length, and thousand-grain weight, respectively—were selected against during domestication to form modern O. sativa(Yu et al., 2021).However, domestication and yield-focused breeding eliminated wild rice's valuable genes(e.g., for disease resistance, stress tolerance, nutrition), narrowing genetic diversity and impeding efforts to meet growing societal demands.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
The multiplexing ability of a novel multiplexing fiber Bragg grating(FBG)method based on Optical Time Domain Reflecto meter(OTDR)and Time Division Multiplexing TDM technologies has been theoretically analyzed and stud...The multiplexing ability of a novel multiplexing fiber Bragg grating(FBG)method based on Optical Time Domain Reflecto meter(OTDR)and Time Division Multiplexing TDM technologies has been theoretically analyzed and studied.This method permits the interrogation of hundreds of identical FBGs with low reflectivity in a single fiber,making the FBG sensors more applicable in the aerospace health monitoring engineering.The analysis shows that the multiplexing ability can be greatly improved if the FBG reflectivity is sufficiently low.And hence,an inexpensive large-scale distributed sensing system based on this method can be realized,When evaluating the multiplexing ability of this system,we propose for the first time that the interference effect of multi-reflections among FBGs should be taken into consideration.展开更多
Color metasurface holograms are powerful and versatile platforms for modulating the amplitude,phase,polarization,and other properties of light at multiple operating wavelengths.However,the current color metasurface ho...Color metasurface holograms are powerful and versatile platforms for modulating the amplitude,phase,polarization,and other properties of light at multiple operating wavelengths.However,the current color metasurface holography can only realize static manipulation.In this study,we propose and demonstrate a multiplexing metasurface technique combined with multiwavelength code-division multiplexing(CDM)to realize dynamic manipulation.Multicolor code references are utilized to record information within a single metasurface and increase the information capacity and security for anticracks.A total of 48 monochrome images consisting of pure color characters and multilevel color video frames were reconstructed in dual polarization channels of the birefringent metasurface to exhibit high information density,and a video was displayed via sequential illumination of the corresponding code patterns to verify the ability of dynamic manipulation.Our approach demonstrates significant application potential in optical data storage,optical encryption,multiwavelengthversatile diffractive optical elements,and stimulated emission depletion microscopy.展开更多
As a promising counterpart of two-dimensional metamaterials,metasurfaces enable to arbitrarily control the wavefront of light at subwavelength scale and hold promise for planar holography and applicable multiplexing d...As a promising counterpart of two-dimensional metamaterials,metasurfaces enable to arbitrarily control the wavefront of light at subwavelength scale and hold promise for planar holography and applicable multiplexing devices.Nevertheless,the degrees of freedom(DoF)to orthogonally multiplex data have been almost exhausted.Compared with state-of-theart methods that extensively employ the orthogonal basis such as wavelength,polarization or orbital angular momentum,we propose an unprecedented method of peristrophic multiplexing by combining the spatial frequency orthogonality with the subwavelength detour phase principle.The orthogonal relationship between the spatial frequency of incident light and the locally shifted building blocks of metasurfaces can be regarded as an additional DoF.We experimentally demonstrate the viability of the multiplexed holograms.Moreover,this newly-explored orthogonality is compatible with conventional DoFs.Our findings will contribute to the development of multiplexing metasurfaces and provide a novel solution to nanophotonics,such as large-capacity chip-scale devices and highly integrated communication.展开更多
基金supported by the National Natural Science Foundation of China under Grant Nos.62022022 and 62101107the National Key R&D Program of China under Grant No.2018YFB1801502+1 种基金China Postdoctoral Science Foundation under Grant No.2021TQ0057ZTE Industry-Uni⁃versity-Institute Cooperation Funds.
文摘With the development of wireless communication,the 6G mobile communication technology has received wide attention.As one of the key technologies of 6G,terahertz(THz)communication technology has the characteristics of ultra-high bandwidth,high security and low environmental noise.In this paper,a THz duplexer with a half-wavelength coupling structure and a sub-harmonic mixer operating at 216 GHz and 204 GHz are designed and measured.Based on these key devices,a 220 GHz frequency-division multiplexing communication system is proposed,with a real-time data rate of 10.4 Gbit/s for one channel and a transmission distance of 15 m.The measured constellation diagram of two receivers is clearly visible,the signal-to-noise ratio(SNR)is higher than 22 dB,and the bit error ratio(BER)is less than 10^(−8).Furthermore,the high definition(HD)4K video can also be transmitted in real time without stutter.
基金supported by the National High Technology Research and Development Program of China(Grant No.2009AA01A345)the National Basic Research Program of China(Grant No.2011CB302702)the National Natural Science Foundation of China(Grant No.60932004)
文摘This paper introduces a joint nonlinearity and chromatic dispersion pre-compensation method for coherent optical orthogonal frequency-division multiplexing systems. The research results show that this method can reduce the walk- off effect and can therefore equalize the nonlinear impairments effectively. Compared with the only other existing nonlinearity pre-compensation method, the joint nonlinearity and chromatic dispersion pre-compensation method is not only suitable for low-dispersion optical orthogonal frequency-division multiplexing system, but also effective for high- dispersion optical orthogonal frequency-division multiplexing transmission system with higher input power but without optical dispersion compensation. The suggested solution does not increase computation complexity compared with only nonlinearity pre-compensation method. For 40 Gbit/s coherent optical orthogonal frequency-division multiplexing 20 × 80 km standard single-mode fibre system, the suggested method can improve the nonlinear threshold （for Q 〉 10 dB） about 2.7, 1.2 and 1.0 dB, and the maximum Q factor about 1.2, 0.4 and 0.3 dB, for 2, 8 and 16 ps/（nm.km） dispersion coefficients.
基金ACKNOWLEDGEMENT This work was supported in part by the Na- tional Natural Science Foundation of China un- der Grants No. 60972072, No. 61340033 and the 111 Project of China under Grant No. B08038.
文摘This paper presents a novel spec- trum sharing design aiming at optimising the performance of a Multiuser Orthogonal Freq- uency-Division Multiplexing （MU-OFDM） Co- gnitive Radio Network （CRN） that consists of multiple secondary Transmitter-Receiver （Tx-Rx） pairs. For most MU-OFDM systems, the Exc- lusive Subchannel Assignment （ESA） is an efficient resource allocation method. Noneth- eless, it is inappropriate for the network consi- dered in this paper, because subchannels shar- ing among secondary Tx-Rx pairs can further improve the system performance. We investi- gate the Weighted Sum Rate （WSR） maximi- zation problem under the Shared Subchannel Assignment （SSA）, where each subchannel is shared by multiple secondary Tx-Rx pairs. With Lagrangian duality technique, we decompose the original resource allocation problem into sev- eral sub-problems on each subchannel and pro- pose a duality-based suhchannel sharing ap- proach. For practical realisation in the cogni- tive systems without central control entity, a distributed duality-based WSR maximization scheme is presented. Simulation results mani- fest that the proposed scheme achieves sig- nificantly better performance than ESA duality scheme.
基金the finanical support from National Natural Science Foundation of China(52127810,51835007,51721003).
文摘An optical frequency comb(OFC)frequency-division multiplexing dispersive interference multichannel distance measurement method is proposed.Based on the OFC dispersive interference,the wide OFC spectrum is divided into multiple channels using a wavelength-division multiplexer.Under the existing light source and spectrometer,a single interference system can realize six channels of the high-precision parallel absolute distance measurement.The influence of the spectrum width and shape on the performance of the distance measurement channel is analyzed.The ranging accuracy of six channels is higher than±4μm under the optimization of a nonuniform discrete Fourier transform and Hanning window.
基金supported by the National Natural Science Foundation of China(Grant Nos.11734012,62105213,12074267,516022053,and 12174265)the Young Innovative Talents Project of Universities in Guangdong Province(Grant No.2019KQNCX123)+4 种基金the Guangdong Basic and Applied Basic Research Fund(Grant No.2020A1515111037)the Science and Technology Project of Guangdong(Grant No.2020B010190001)the Guangdong Natural Science Foundation(Grant No.2020A1515010467)the Shenzhen Fundamental Research Program(Grant No.20200814113625003)the Open Fund of State Key Laboratory of Applied Optics(Grant No.SKLAO2020001A06)。
文摘The rapidly growing global data usage has demanded more efficient ways to utilize the scarce electromagnetic spectrum resource. Recent research has focused on the development of efficient multiplexing techniques in the millimeter-wave band(1-10 mm, or 30-300 GHz) due to the promise of large available bandwidth for future wireless networks. Frequency-division multiplexing is still one of the most commonly-used techniques to maximize the transmission capacity of a wireless network.Based on the frequency-selective tunnelling effect of the low-loss epsilon-near-zero metamaterial waveguide, we numerically and experimentally demonstrate five-channel frequency-division multiplexing and demultiplexing in the millimeter-wave range.We show that this device architecture offers great flexibility to manipulate the filter Q-factors and the transmission spectra of different channels, by changing of the epsilon-near-zero metamaterial waveguide topology and by adding a standard waveguide between two epsilon-near-zero channels. This strategy of frequency-division multiplexing may pave a way for efficiently allocating the spectrum for future communication networks.
基金Supported by the Basic Research Foundation of Tsinghua Na-tional Laboratory for Information Science and Technology (TNList) the Major Program of the National Natural Science Foundation of China (No. 60496311)
文摘Orthogonal frequency-division multiplexing （OFDM） systems are sensitive to carrier frequency offset （CFO） which introduces intercarder interference and significantly degrades system performance. This paper describes an iterative blind receiver consisting of a sequential Monte Carlo detector, a CFO estimator, and a compensator to reduce intercarrier interference. The framework is of low complexity due to the separation of tasks in a joint detection problem. In addition, the CFO estimator utilizes soft output of the sequential Monte Carlo detector, which reduces the information loss caused by hard decisions and can obtain the CFO estimate in only one OFDM symbol. Simulation results demonstrate the effectiveness of the algorithm.
基金supported by the National Natural Science Foundation of China (No. 61177071)the National "863" Program of China (No. 2013AA013603)
文摘We propose a two-cascaded, constant-resistance, symmetrical bridged-T amplitude equalizer for a high-speed visible light communication（VLC） system. With the pre-equalization circuit, the-3 d B bandwidth of the VLC system can be extended from 12 to 235 MHz using a commercially available phosphorescent white light-emitting diode（LED）, a blue filter, and a low-cost PIN photodiode. The data rate is 1.20 Gbit/s, exploiting 16-quadrature amplitude modulation-orthogonal frequency-division multiplexing with a 300 MHz modulation bandwidth over50 cm of free-space transmission under the pre-forward error correction limit of 3.8 × 10^-3. To our knowledge,this is the highest-3 d B bandwidth and the highest data rate ever achieved by using a pre-equalization circuit and white LED in a VLC system.
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(Grants U22A2008,12404484,12464016,and 62405219)the Double First Class Joint Special Key Project of Yunnan Science and Technology Department and Yunnan University(Grant 202401BF070001-012)Sichuan Provincial Science and Technology Support Program(Grant 25QNJJ2419).
文摘Dynamically tunable terahertz(THz)beam focusing plays a critical role in emerging applications including reconfigurable imaging,localized spectral analysis,and micro-machining.Conventional methods,however,frequently employ complex wavefront modulators and external control algorithms,resulting in increased system footprint and limited tuning efficiency.In this work,we present an all-silicon mechanically rotatable cascaded metasurface capable of dynamic THz beam focusing.By independently adjusting the relative rotation angles between the two metasurface layers,real-time repositioning of the focal spot is achieved for orthogonal circular polarization channels.The proposed design facilitates polarization-division multiplexing without requiring external algorithms or active materials while preserving high focusing efficiency and beam quality across a predefined focal plane.Numerical simulations reveal a quasi-linear shift of the focal position with the rotation angle,with stable focusing efficiency and full-width at half-maximum observed in both polarization channels.This strategy offers an efficient and reliable approach to dynamic wavefront control for compact,reconfigurable THz imaging,sensing,and communication systems.
文摘The exponential growth in data traffic has driven significant research into maximizing the capacity of free-space optical(FSO)communication systems.Orbital angular momentum(OAM)multiplexing offers a promising approach by using spatially structured beams with helical wavefronts to achieve higher data transmission rates.However,conventional electronic convolutional-neural-network-based OAM demultiplexing schemes exhibit substantial computational and energy efficiency limitations.
基金National Key Research and Development Program of China(2023YFB2905502)Explorers Program of Shanghai(Basic Research Funding)(24TS1401000)。
文摘In this work,a reflective metasurface connector(RMC)and its application for high-density and wideband spacedivision multiplexing(SDM)are demonstrated.This device features single facet metasurface fabrication over an SOI platform based on a CMOS compatible process.A minimum fiber-to-fiber insertion loss of 2.9 dB at 1598.24 nm is realized for fan-in-fan-out(FIFO)applications between a single-mode fiber(SMF)array and a multicore fiber(MCF).
基金supported by grants from the National Key Research and Development Program of China(Nos.2023YFA0915200,2023YFA0915204)the Equipment Research and Development Projects of the Chinese Academy of Sciences(No.PTYQ2024YZ0010)+3 种基金the Science and Technology Commission of Shanghai Municipality Project(No.XTCX-KJ-2024-038)the Natural Science Foundation of Hebei Province of China(No.H2024206249)the Postdoctoral Fellowship Program of CPSF(No.GZC20232838)Science and Technology Commission of Shanghai Municipality(No.22S31901700).
文摘The implementation of multiple pathogen testing is essential for a rapid response to future outbreaks and for reducing disease transmission.This study introduces a 96-channel microfluidic chip,fabricated through a molding process,which enables the batch detection of pathogens.It explores the rapid lysis and elution processes of pathogens within the microfluidic chips to ensure that nucleic acid extraction,elution,and amplification are completed entirely within the chip.This chip can extract nucleic acids from samples in just 10 min,achieving an extraction efficiency comparable to that of traditional in-tube methods.An oil phase is pre-loaded into the chip to effectively prevent aerosol contamination.This approach allows for the simultaneous detection of 21 common respiratory pathogens,with a detection limit of 10 copies per reaction.Furthermore,applications involving clinical samples demonstrate significant practicality.Compared to many traditional in-tube pathogen detection methods and molecular biology technologies that utilize microfluidic chips,this detection chip not only enables simultaneous detection of multiple pathogens but also demonstrates high sensitivity.
基金supported by the Biological BreedingMajor Projects(2023ZD04076)the National Natural Science Foundation of China(32300312)+2 种基金the Innovation Program of Chinses Academy of Agricultural Sciences(CAAS-CSIAF-202303)the Guangdong Basic and Applied Basic Research Foundation(2020B1515120086)the KeyArea Research and Development Program of Guangdong Province(2021B0707010006)。
文摘Rice, a global staple food, is critical for food security. The cultivated Oryza sativa, domesticated from wild O. rufipogon, derives~80%of its 993 identified domestication-related genes from O. rufipogon and 20%from South/Southeast Asian wild O. nivara(Jing et al., 2023). Genes like An-1, BH4, PROG1,SH4, Rc, Rd, and GS3—which regulate awn length, hull color,til er angle, seed shattering, pericarp color, seed length, and thousand-grain weight, respectively—were selected against during domestication to form modern O. sativa(Yu et al., 2021).However, domestication and yield-focused breeding eliminated wild rice's valuable genes(e.g., for disease resistance, stress tolerance, nutrition), narrowing genetic diversity and impeding efforts to meet growing societal demands.
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.
基金Foundation item:National Natural Science Foundation of China(10376001)
文摘The multiplexing ability of a novel multiplexing fiber Bragg grating(FBG)method based on Optical Time Domain Reflecto meter(OTDR)and Time Division Multiplexing TDM technologies has been theoretically analyzed and studied.This method permits the interrogation of hundreds of identical FBGs with low reflectivity in a single fiber,making the FBG sensors more applicable in the aerospace health monitoring engineering.The analysis shows that the multiplexing ability can be greatly improved if the FBG reflectivity is sufficiently low.And hence,an inexpensive large-scale distributed sensing system based on this method can be realized,When evaluating the multiplexing ability of this system,we propose for the first time that the interference effect of multi-reflections among FBGs should be taken into consideration.
基金the National Key R&D Program of China(2021YFA1401200)Beijing Outstanding Young Scientist Program(BJJWZYJH01201910007022)+2 种基金National Natural Science Foundation of China(No.U21A20140,No.92050117)Beijing Municipal Science&Technology Commission,Administrative Commission of Zhongguancun Science Park(No.Z211100004821009)X.Li acknowledges the support from Beijing Institute of Technology Research Fund Program for Young Scholars(XSQD-201904005).
文摘Color metasurface holograms are powerful and versatile platforms for modulating the amplitude,phase,polarization,and other properties of light at multiple operating wavelengths.However,the current color metasurface holography can only realize static manipulation.In this study,we propose and demonstrate a multiplexing metasurface technique combined with multiwavelength code-division multiplexing(CDM)to realize dynamic manipulation.Multicolor code references are utilized to record information within a single metasurface and increase the information capacity and security for anticracks.A total of 48 monochrome images consisting of pure color characters and multilevel color video frames were reconstructed in dual polarization channels of the birefringent metasurface to exhibit high information density,and a video was displayed via sequential illumination of the corresponding code patterns to verify the ability of dynamic manipulation.Our approach demonstrates significant application potential in optical data storage,optical encryption,multiwavelengthversatile diffractive optical elements,and stimulated emission depletion microscopy.
基金supported by the Science and Technology Projects of Innovation Laboratory for Sciences and Technologies of Energy Materials of Fujian Province(IKKEM)No.HRTP202231partially supported by the Agency for Science,Technology,and Research(A*STAR)under AME IRG Grant Nos.A20E5c0095,and CDF Grant No.C210112044。
文摘As a promising counterpart of two-dimensional metamaterials,metasurfaces enable to arbitrarily control the wavefront of light at subwavelength scale and hold promise for planar holography and applicable multiplexing devices.Nevertheless,the degrees of freedom(DoF)to orthogonally multiplex data have been almost exhausted.Compared with state-of-theart methods that extensively employ the orthogonal basis such as wavelength,polarization or orbital angular momentum,we propose an unprecedented method of peristrophic multiplexing by combining the spatial frequency orthogonality with the subwavelength detour phase principle.The orthogonal relationship between the spatial frequency of incident light and the locally shifted building blocks of metasurfaces can be regarded as an additional DoF.We experimentally demonstrate the viability of the multiplexed holograms.Moreover,this newly-explored orthogonality is compatible with conventional DoFs.Our findings will contribute to the development of multiplexing metasurfaces and provide a novel solution to nanophotonics,such as large-capacity chip-scale devices and highly integrated communication.
