Complex-valued double-sideband direct detection(DD)can reconstruct the optical field and achieve a high electrical spectral efficiency(ESE)comparable to that of a coherent homodyne receiver,and DD does not require a c...Complex-valued double-sideband direct detection(DD)can reconstruct the optical field and achieve a high electrical spectral efficiency(ESE)comparable to that of a coherent homodyne receiver,and DD does not require a costly local oscillator laser.However,a fundamental question remains if there is an optimal DD receiver structure with the simplest design to approach the performance of the coherent homodyne detection.This study derives the optimal DD receiver structure with an optimal transfer function to recover a quadrature amplitude modulation(QAM)signal with a near-zero guard band at the central frequency of the signal.We derive the theoretical ESE limit for various detection schemes by invoking Shannon’s formula.Our proposed scheme is closest to coherent homodyne detection in terms of the theoretical ESE limit.By leveraging a WaveShaper to construct the optimal transfer function,we conduct a proof-of-concept experiment to transmit a net 228.85-Gb/s 64-QAM signal over an 80-km single-mode fiber with a net ESE of 8.76 b/s/Hz.To the best of our knowledge,this study reports the highest net ESE per polarization per wavelength for DD transmission beyond 40-km single-mode fiber.For a comprehensive metric,denoted as 2ESE×Reach,we achieve the highest 2ESE×Reach per polarization per wavelength for DD transmission.展开更多
Thinopyrum intermedium has been used as a resource for improving resistance to biotic and abiotic stresses and yield potential in common wheat. Wheat line SN304 was derived from a cross between common wheat cultivar Y...Thinopyrum intermedium has been used as a resource for improving resistance to biotic and abiotic stresses and yield potential in common wheat. Wheat line SN304 was derived from a cross between common wheat cultivar Yannong 15 and Th. intermedium. Genomic in situ hybridization(GISH) produced no hybridization signal in SN304 using Th. intermedium genomic DNA as a probe, but fluorescence in situ hybridization(FISH) using oligonucleotides AFA-3, AFA-4, pAs1-1, pAs1-3, pAs1-4, pAs1-6, pSc119.2-1,and(GAA)10 as probes detected hybridization signals on chromosomes 2 A, 7 A, 2 B, 3 B, 6 B, and 7 B in SN304 that differed from Yannong 15. Results of specific markers also indicated that there were Th. intermedium chromatin introgressions on different chromosomes in SN304. In a hydroponic culture experiment, SN304 not only produced more biomass and higher stem and leaf dry weight but also accumulated more phosphorus than Yannong 15 under phosphorus-deficiency stress. Moreover, SN304 produced a lower pH and released more organic acids, especially oxalic acid, than Yannong 15, which suggests that SN304 exudates enabled more absorbance of P than Yannong 15 under comparable conditions.The results indicate that SN304 is a wheat-Th. intermedium introgression line with tolerance to phosphorus-deficiency stress.展开更多
As a staple food crop for one-third of the world＇s population, common wheat （Triticum aestivum L., 2n = 6x = 42, AABBDD） plays an important role in humans＇ food security. However, the genetic variation of cultivat...As a staple food crop for one-third of the world＇s population, common wheat （Triticum aestivum L., 2n = 6x = 42, AABBDD） plays an important role in humans＇ food security. However, the genetic variation of cultivated wheat has been dramatically narrowed by genetic erosion under the modem cultivation system, resulting in vulnerability to biotic and abiotic stresses （Jiang et al., 1994; Friebe et al., 1996）. The wild relatives of wheat represent a large reservoir of superior genes, and transferring these alien genes to modem cultivars through chromosome engineering is a successful method of broadening the genetic diversity of wheat （Chen et al., 2003;展开更多
Dear Editor,Crop pathogens cause substantial economic losses and reduce food security globally.Harnessing disease resistance genes and breeding resistant crops are the most effective ways to reduce losses caused by pa...Dear Editor,Crop pathogens cause substantial economic losses and reduce food security globally.Harnessing disease resistance genes and breeding resistant crops are the most effective ways to reduce losses caused by pathogens.Domestication and cultivar breeding of wheat and other crops have significantly reduced their genetic diversity.The reduced diversity has resulted in a shortage of disease resistance genes,which is a severe obstacle for wheat breeding.展开更多
An efficient and green copper（Ⅱ） acetylacetonate-catalyzed protocol for the Huisgen-click reaction in water at 100℃ has been established. The protocol was not only suitable for the reaction between organic azides ...An efficient and green copper（Ⅱ） acetylacetonate-catalyzed protocol for the Huisgen-click reaction in water at 100℃ has been established. The protocol was not only suitable for the reaction between organic azides and alkynes, but also suitable for one-pot three-component reaction among alkyl halides, NaN3 and alkynes.展开更多
On-chip spatial mode operation,represented as mode-division multiplexing(MDM),can support high-capacity data communications and promise superior performance in various systems and numerous applications from optical se...On-chip spatial mode operation,represented as mode-division multiplexing(MDM),can support high-capacity data communications and promise superior performance in various systems and numerous applications from optical sensing to nonlinear and quantum optics.However,the scalability of state-of-the-art mode manipulation techniques is significantly hindered not only by the particular mode-order-oriented design strategy but also by the inherent limitations of possibly achievable mode orders.Recently,metamaterials capable of providing subwavelength-scale control of optical wavefronts have emerged as an attractive alternative to manipulate guided modes with compact footprints and broadband functionalities.Herein,we propose a universal yet efficient design framework based on the topological metamaterial building block(BB),enabling the excitation of arbitrary high-order spatial modes in silicon waveguides.By simply programming the layout of multiple fully etched dielectric metamaterial perturbations with predefined mathematical formulas,arbitrary high-order mode conversion and mode exchange can be simultaneously realized with uniform and competitive performance.The extraordinary scalability of the metamaterial BB frame is experimentally benchmarked by a record high-order mode operator up to the twentieth.As a proof of conceptual application,an 8-mode MDM data transmission of 28-GBaud 16-QAM optical signals is also verified with an aggregate data rate of 813 Gb/s(7%FEC).This user-friendly metamaterial BB concept marks a quintessential breakthrough for comprehensive manipulation of spatial light on-chip by breaking the long-standing shackles on the scalability,which may open up fascinating opportunities for complex photonic functionalities previously inaccessible.展开更多
Topologically protected edge states based on valley photonic crystals(VPCs)have been widely studied,from theoretical verifcation to technical applications.However,research on integrated tuneable topological devices is...Topologically protected edge states based on valley photonic crystals(VPCs)have been widely studied,from theoretical verifcation to technical applications.However,research on integrated tuneable topological devices is still lacking.Here,we study the phase-shifting theory of topological edge modes based on a VPC structure.Benefiting from the phase vortex formed by the VPC structure,the optical path of the topological edge mode in the propagation direction is approximately two-fold that of the conventional optical mode in a strip waveguide.In experiments,we show a 1.57-fold improvement inπ-phase tuning efficiency.By leveraging the highefficiency phase-shifting properties and the sharp-turn features of the topological waveguide,we demonstrate an ultracompact 1×2 thermo-optic topological switch(TOTS)operating at telecommunication wavelengths.A switching power of 18.2 mW is needed with an ultracompact device footprint of 25.66×28.3μm in the wavelength range of 1530-1582 nm.To the best of our knowledge,this topological photonic switch is the smallest switch of any dielectric or semiconductor 1×2/2×2 broadband optical switches,including thermo-optic and electro-optic switches.In addition,a high-speed transmission experiment employing the proposed TOTS is carried out to demonstrate the robust transmission of high-speed data.Our work reveals the phase shifting mechanism of valley edge modes,which may enable diverse topological functional devices in many fields,such as optical communications,nanophotonics,and quantum information processing.展开更多
Mode-division multiplexing(MDM)technology enables high-bandwidth data transmission using orthogonal waveguide modes to construct parallel data streams.However,few demonstrations have been realized for generating and s...Mode-division multiplexing(MDM)technology enables high-bandwidth data transmission using orthogonal waveguide modes to construct parallel data streams.However,few demonstrations have been realized for generating and supporting high-order modes,mainly due to the intrinsic large material groupvelocity dispersion(GVD),which make it challenging to selectively couple different-order spatial modes.We show the feasibility of on-chip GVD engineering by introducing a gradient-index metamaterial structure,which enables a robust and fully scalable MDM process.We demonstrate a record-high-order MDM device that supports TE_(0)–TE_(15)modes simultaneously.40-GBaud 16-ary quadrature amplitude modulation signals encoded on 16 mode channels contribute to a 2.162 Tbit∕s net data rate,which is the highest data rate ever reported for an on-chip single-wavelength transmission.Our method can effectively expand the number of channels provided by MDM technology and promote the emerging research fields with great demand for parallelism,such as high-capacity optical interconnects,high-dimensional quantum communications,and large-scale neural networks.展开更多
基金supported by the National Natural Science Foundation of China(62341508).
文摘Complex-valued double-sideband direct detection(DD)can reconstruct the optical field and achieve a high electrical spectral efficiency(ESE)comparable to that of a coherent homodyne receiver,and DD does not require a costly local oscillator laser.However,a fundamental question remains if there is an optimal DD receiver structure with the simplest design to approach the performance of the coherent homodyne detection.This study derives the optimal DD receiver structure with an optimal transfer function to recover a quadrature amplitude modulation(QAM)signal with a near-zero guard band at the central frequency of the signal.We derive the theoretical ESE limit for various detection schemes by invoking Shannon’s formula.Our proposed scheme is closest to coherent homodyne detection in terms of the theoretical ESE limit.By leveraging a WaveShaper to construct the optimal transfer function,we conduct a proof-of-concept experiment to transmit a net 228.85-Gb/s 64-QAM signal over an 80-km single-mode fiber with a net ESE of 8.76 b/s/Hz.To the best of our knowledge,this study reports the highest net ESE per polarization per wavelength for DD transmission beyond 40-km single-mode fiber.For a comprehensive metric,denoted as 2ESE×Reach,we achieve the highest 2ESE×Reach per polarization per wavelength for DD transmission.
基金supported by the National Key Research and Development Program of China(2016YFD0102000)National Natural Science Foundation of China(31671675)Natural Science Foundation of Shandong Province(ZR2015CM034 and ZR2016CM30)。
文摘Thinopyrum intermedium has been used as a resource for improving resistance to biotic and abiotic stresses and yield potential in common wheat. Wheat line SN304 was derived from a cross between common wheat cultivar Yannong 15 and Th. intermedium. Genomic in situ hybridization(GISH) produced no hybridization signal in SN304 using Th. intermedium genomic DNA as a probe, but fluorescence in situ hybridization(FISH) using oligonucleotides AFA-3, AFA-4, pAs1-1, pAs1-3, pAs1-4, pAs1-6, pSc119.2-1,and(GAA)10 as probes detected hybridization signals on chromosomes 2 A, 7 A, 2 B, 3 B, 6 B, and 7 B in SN304 that differed from Yannong 15. Results of specific markers also indicated that there were Th. intermedium chromatin introgressions on different chromosomes in SN304. In a hydroponic culture experiment, SN304 not only produced more biomass and higher stem and leaf dry weight but also accumulated more phosphorus than Yannong 15 under phosphorus-deficiency stress. Moreover, SN304 produced a lower pH and released more organic acids, especially oxalic acid, than Yannong 15, which suggests that SN304 exudates enabled more absorbance of P than Yannong 15 under comparable conditions.The results indicate that SN304 is a wheat-Th. intermedium introgression line with tolerance to phosphorus-deficiency stress.
基金supported by a grant from the National High Technology Research and Development Program("863" Program) of China(No. 2011AA100103)
文摘As a staple food crop for one-third of the world＇s population, common wheat （Triticum aestivum L., 2n = 6x = 42, AABBDD） plays an important role in humans＇ food security. However, the genetic variation of cultivated wheat has been dramatically narrowed by genetic erosion under the modem cultivation system, resulting in vulnerability to biotic and abiotic stresses （Jiang et al., 1994; Friebe et al., 1996）. The wild relatives of wheat represent a large reservoir of superior genes, and transferring these alien genes to modem cultivars through chromosome engineering is a successful method of broadening the genetic diversity of wheat （Chen et al., 2003;
基金supported by the Key R&D Program of Shandong Province,China(2024LZGC001,2023TZXD086)The public re-sequencing data of rye germplasm were obtained from the NCBI database(accession numbers PRJNA737291,PRJEB6215,and PRJEB34439)the National Genomics Data Center of China(accession number PRJCA006012)。
文摘Dear Editor,Crop pathogens cause substantial economic losses and reduce food security globally.Harnessing disease resistance genes and breeding resistant crops are the most effective ways to reduce losses caused by pathogens.Domestication and cultivar breeding of wheat and other crops have significantly reduced their genetic diversity.The reduced diversity has resulted in a shortage of disease resistance genes,which is a severe obstacle for wheat breeding.
文摘An efficient and green copper（Ⅱ） acetylacetonate-catalyzed protocol for the Huisgen-click reaction in water at 100℃ has been established. The protocol was not only suitable for the reaction between organic azides and alkynes, but also suitable for one-pot three-component reaction among alkyl halides, NaN3 and alkynes.
基金supported by National Key R&D Program of China(2019YFB2203101)Natural Science Foundation of China(NSFO)(62175151,61835008)+1 种基金Natural Science Foundation of Shanghai(19ZR1475400)Open Project Program of Wuhan National Laboratory for Optoelectrornics(2018WNLOKF012).
文摘On-chip spatial mode operation,represented as mode-division multiplexing(MDM),can support high-capacity data communications and promise superior performance in various systems and numerous applications from optical sensing to nonlinear and quantum optics.However,the scalability of state-of-the-art mode manipulation techniques is significantly hindered not only by the particular mode-order-oriented design strategy but also by the inherent limitations of possibly achievable mode orders.Recently,metamaterials capable of providing subwavelength-scale control of optical wavefronts have emerged as an attractive alternative to manipulate guided modes with compact footprints and broadband functionalities.Herein,we propose a universal yet efficient design framework based on the topological metamaterial building block(BB),enabling the excitation of arbitrary high-order spatial modes in silicon waveguides.By simply programming the layout of multiple fully etched dielectric metamaterial perturbations with predefined mathematical formulas,arbitrary high-order mode conversion and mode exchange can be simultaneously realized with uniform and competitive performance.The extraordinary scalability of the metamaterial BB frame is experimentally benchmarked by a record high-order mode operator up to the twentieth.As a proof of conceptual application,an 8-mode MDM data transmission of 28-GBaud 16-QAM optical signals is also verified with an aggregate data rate of 813 Gb/s(7%FEC).This user-friendly metamaterial BB concept marks a quintessential breakthrough for comprehensive manipulation of spatial light on-chip by breaking the long-standing shackles on the scalability,which may open up fascinating opportunities for complex photonic functionalities previously inaccessible.
基金the National Key R&D Program of China under grant 2019YFB1803903the National Natural Science Foundation of China(NSFC)(61860206001,61835008,62035016,62105200,61975115 and 12122407)。
文摘Topologically protected edge states based on valley photonic crystals(VPCs)have been widely studied,from theoretical verifcation to technical applications.However,research on integrated tuneable topological devices is still lacking.Here,we study the phase-shifting theory of topological edge modes based on a VPC structure.Benefiting from the phase vortex formed by the VPC structure,the optical path of the topological edge mode in the propagation direction is approximately two-fold that of the conventional optical mode in a strip waveguide.In experiments,we show a 1.57-fold improvement inπ-phase tuning efficiency.By leveraging the highefficiency phase-shifting properties and the sharp-turn features of the topological waveguide,we demonstrate an ultracompact 1×2 thermo-optic topological switch(TOTS)operating at telecommunication wavelengths.A switching power of 18.2 mW is needed with an ultracompact device footprint of 25.66×28.3μm in the wavelength range of 1530-1582 nm.To the best of our knowledge,this topological photonic switch is the smallest switch of any dielectric or semiconductor 1×2/2×2 broadband optical switches,including thermo-optic and electro-optic switches.In addition,a high-speed transmission experiment employing the proposed TOTS is carried out to demonstrate the robust transmission of high-speed data.Our work reveals the phase shifting mechanism of valley edge modes,which may enable diverse topological functional devices in many fields,such as optical communications,nanophotonics,and quantum information processing.
基金supported by the National Key R&D Program of China(Grant No.2021YFB2800103)National Natural Science Foundation of China(NSFC)(Grant Nos.62105202,61835008,61860206001,61975115,62035016,and 62105200).
文摘Mode-division multiplexing(MDM)technology enables high-bandwidth data transmission using orthogonal waveguide modes to construct parallel data streams.However,few demonstrations have been realized for generating and supporting high-order modes,mainly due to the intrinsic large material groupvelocity dispersion(GVD),which make it challenging to selectively couple different-order spatial modes.We show the feasibility of on-chip GVD engineering by introducing a gradient-index metamaterial structure,which enables a robust and fully scalable MDM process.We demonstrate a record-high-order MDM device that supports TE_(0)–TE_(15)modes simultaneously.40-GBaud 16-ary quadrature amplitude modulation signals encoded on 16 mode channels contribute to a 2.162 Tbit∕s net data rate,which is the highest data rate ever reported for an on-chip single-wavelength transmission.Our method can effectively expand the number of channels provided by MDM technology and promote the emerging research fields with great demand for parallelism,such as high-capacity optical interconnects,high-dimensional quantum communications,and large-scale neural networks.
