Pump valve pipeline vibration brings serious safety hazards to the operation of the equipment,for the pump valve system in the process of variable flow,variable speed,variable openings lead to excessive pipeline vibra...Pump valve pipeline vibration brings serious safety hazards to the operation of the equipment,for the pump valve system in the process of variable flow,variable speed,variable openings lead to excessive pipeline vibration.An active damping device(ADD)is used to the vibration of the pump valve pipeline system to apply the control force,to achieve the active control of the pipeline vibration.A pump-valve pipeline vibration test bench was built to compare the control effect of active damping device on pipeline vibration under different pump valve working conditions,and the results show that applying ADD control could effectively suppress the vibration of the pump valve pipeline and enhance the stability of the equipment during operation.At different pump operating rotation frequencies,the vibration amplitude of the pump valve pipeline in working frequency and its multiple frequencies are also effectively suppressed,with the maximum amplitude reduction of more than 60%.For the valve vibration caused by different operating openings,the vibration of the highest reduction of 68%,and the centrifugal pump drive shaft vi-bration reduced by up to 73%,which provides a new idea for vibration control of pump valve pipeline system.展开更多
A simplified simulation method based on the FDTD technique that can handle active devices is proposed. This method well suits the electrical crosstalk analysis of multi-channel integrated, opto-electronic mixed module...A simplified simulation method based on the FDTD technique that can handle active devices is proposed. This method well suits the electrical crosstalk analysis of multi-channel integrated, opto-electronic mixed modules. We apply this method to an 8-channel integrated super-compact high-sensitivity optical module. The results show good agreement between simulations and measurements.展开更多
The development of precise and sensitive electrophysiological recording platforms holds the utmost importance for research in the fields of cardiology and neuroscience.In recent years,active micro/nano-bioelectronic d...The development of precise and sensitive electrophysiological recording platforms holds the utmost importance for research in the fields of cardiology and neuroscience.In recent years,active micro/nano-bioelectronic devices have undergone significant advancements,thereby facilitating the study of electrophysiology.The distinctive configuration and exceptional functionality of these active micro-nano-collaborative bioelectronic devices offer the potential for the recording of high-fidelity action potential signals on a large scale.In this paper,we review three-dimensional active nano-transistors and planar active micro-transistors in terms of their applications in electroexcitable cells,focusing on the evaluation of the effects of active micro/nano-bioelectronic devices on electrophysiological signals.Looking forward to the possibilities,challenges,and wide prospects of active micro-nano-devices,we expect to advance their progress to satisfy the demands of theoretical investigations and medical implementations within the domains of cardiology and neuroscience research.展开更多
Organic optoelectronic integrated devices（OIDs） with ultraviolet（UV） photodetectivity and different color emitting were constructed by using a thermally activated delayed fluorescence（TADF） material 4, 5-bis（ca...Organic optoelectronic integrated devices（OIDs） with ultraviolet（UV） photodetectivity and different color emitting were constructed by using a thermally activated delayed fluorescence（TADF） material 4, 5-bis（carbazol-9-yl）-1, 2-dicyanobenzene（2 CzPN） as host. The OIDs doping with typical red phosphorescent dye [tris（1-phenylisoquinoline）iridium（Ⅲ）, Ir（piq）3], orange phosphorescent dye {bis[2-（4-tertbutylphenyl）benzothiazolato-N,C-（2＇）]iridium（acetylacetonate）,（tbt）2 Ir（acac）}, and blue phosphorescent dye [bis（2, 4-di-fluorophenylpyridinato）-tetrakis（1-pyrazolyl）borate iridium（Ⅲ）, FIr6] were investigated and compared. The（tbt）2 Ir（acac）-doped orange device showed better performance than those of red and blue devices, which was ascribed to more effective energy transfer. Meanwhile, at a low dopant concentration of 3 wt.%, the（tbt）2 Ir（acac）-doped OIDs showed the maximum luminance, current efficiency, power efficiency of 70786 cd/m^2, 39.55 cd/A, and 23.92 lm/W, respectively, and a decent detectivity of 1.07 × 10^11 Jones at a bias of -2 V under the UV-350 nm illumination. This work may arouse widespread interest in constructing high efficiency and luminance OIDs based on doping phosphorescent dye.展开更多
Vanadium dioxide （VO2） is a phase transition material which undergoes a reversible metal-insulator transition （MIT） when triggered by thermal, photo, electrical, and even stress. The huge conduction change of VO2 ...Vanadium dioxide （VO2） is a phase transition material which undergoes a reversible metal-insulator transition （MIT） when triggered by thermal, photo, electrical, and even stress. The huge conduction change of VO2 renders it a promising material for terahertz （THz） manipulation. In this paper, some interesting works concerning the growth and characteristics of the VO2 film are selectively reviewed. A switching of THz radiation by photo-driven VO2 film is demonstrated. Experiments indicate an ultrafast optical switching to THz transmission within 8 picoseconds, and a switching ratio reaches to over 80%during a wide frequency range from 0.3 THz to 2.5 THz.展开更多
Given the interdisciplinary challenges in materials sciences, chemistry, physics, and biology, as well as the demands to merge electronics and photonics at the nanometer scale for miniaturized integrated circuits, pla...Given the interdisciplinary challenges in materials sciences, chemistry, physics, and biology, as well as the demands to merge electronics and photonics at the nanometer scale for miniaturized integrated circuits, plasmonics serves as a bridge by breaking the limit in the speed of nanoscale electronics and the size of terahertz dielectric photonics. Active plasmonic systems enabling active control over the plasmonic properties in real time have opened up a wealth of potential applications. This review focuses on the development of active plasmonic response devices. Significant advances have been achieved in control over the dielectric properties of the active surrounding medium, including liquid crystals, polymers, photochromic molecules and inorganic materials, which in turn allows tuning of the reversible plasmon resonance switch of neighboring metal nanostructures.展开更多
Networks based on backscatter communication provide wireless data transmission in the absence of a power source.A backscatter device receives a radio frequency(RF)source and creates a backscattered signal that deliver...Networks based on backscatter communication provide wireless data transmission in the absence of a power source.A backscatter device receives a radio frequency(RF)source and creates a backscattered signal that delivers data;this enables new services in battery-less domains with massive Internet-of-Things(IoT)devices.Connectivity is highly energy-efficient in the context of massive IoT applications.Outdoors,long-range(LoRa)backscattering facilitates large IoT services.A backscatter network guarantees timeslot-and contention-based transmission.Timeslot-based transmission ensures data transmission,but is not scalable to different numbers of transmission devices.If contention-based transmission is used,collisions are unavoidable.To reduce collisions and increase transmission efficiency,the number of devices transmitting data must be controlled.To control device activation,the RF source range can be modulated by adjusting the RF source power during LoRa backscatter.This reduces the number of transmitting devices,and thus collisions and retransmission,thereby improving transmission efficiency.We performed extensive simulations to evaluate the performance of our method.展开更多
In accordance with current problems such as odor pollution,long production period,consumption of a large amount of manpower and so on existing in chicken manure fermentation ,an environment friendly type of chicken ma...In accordance with current problems such as odor pollution,long production period,consumption of a large amount of manpower and so on existing in chicken manure fermentation ,an environment friendly type of chicken manure fermentation device is designed. The key parameters of the equipment are resonance activated tube and fermenting cellar. Resonance activated tube makes the activated water,which could improve obvi- ously the biodegradation rate of chicken manure. The aerator could provide enough oxygen to microbes,and the agitator could make oxygen evenly distributed across the chicken manure in fermenting cellar. The test shows that this equipment is high-efficiency,and only takes 7 days to make the chicken manure achieve the decomposed requirement. The organic matter content of composted chicken manure is 91.2%,C/N ratio is 18.8, MPN is 0.04, mortality of ascarid egg is 99.6% ,concentrations of NH3 and H2 S are 4.20 and 1.58 mg/m3, furthermore ,there is no offensive smell in the fermenting cellar. Therefore,the study can provide a pollution-free, high-efficiency, manpower saving fermentation equipment for organic fertilizer production by chicken manure in agriculture area.展开更多
Electromagnetically induced transparency(EIT)phenomenon is observed in simple metamaterial which consists of concentric double U-shaped resonators(USRs).The numerical and theoretical analysis reveals that EIT arises f...Electromagnetically induced transparency(EIT)phenomenon is observed in simple metamaterial which consists of concentric double U-shaped resonators(USRs).The numerical and theoretical analysis reveals that EIT arises from the bright-bright mode coupling.The transmission spectra at different polarization angle of incident light shows that EIT transparency window is polarization sensitive.More interestingly,Fano resonance appears in the transmission spectrum at certain polarization angles.The sharp and asymmetric Fano lineshape is high valuable for sensing.The performance of sensor is investigated and the sensitivity is high up to 327 GHz/RIU.Furthermore,active control of EIT window is realized by incorporating photosensitive silicon.The proposed USR structure is simple and compact,which may find significant applications in tunable integrated devices such as biosensor,filters,and THz modulators.展开更多
The ability to control nonclassical light emission from a single quantum emitter by an integrated cavity may unleash new perspectives for integrated photonic quantum applications.However,coupling a single quantum emit...The ability to control nonclassical light emission from a single quantum emitter by an integrated cavity may unleash new perspectives for integrated photonic quantum applications.However,coupling a single quantum emitter to cavity within photonic circuitry towards creation of the Purcell-enhanced single-photon emission is elusive due to the complexity of integrating active devices in low-loss photonic circuits.Here we demonstrate a hybrid micro-ring resonator(HMRR)coupled with self-assembled quantum dots(QDs)for cavity-enhanced deterministic single-photon emission.The HMRR cavity supports whispering-gallery modes with quality factors up to 7.8×103.By further introducing a micro-heater,we show that the photon emission of QDs can be locally and dynamically tuned over one free spectral ranges of the HMRR(~4 nm).This allows precise tuning of individual QDs in resonance with the cavity modes,thereby enhancing single-photon emission with a Purcell factor of about 4.9.Our results on the hybrid integrated cavities coupled with two-level quantum emitters emerge as promising devices for chip-based scalable photonic quantum applications.展开更多
Thin-film lithium niobate has attracted great interest in high-speed communication due to its unique piezoelectric and nonlinear properties.However,its high photorefraction and slow electro-optic response relaxation i...Thin-film lithium niobate has attracted great interest in high-speed communication due to its unique piezoelectric and nonlinear properties.However,its high photorefraction and slow electro-optic response relaxation introduce the possibility of transmission bit errors.Recently,lithium tantalate,another piezoelectric and nonlinear material,has emerged as a promising candidate for active photonic integrated devices because of its weaker photorefraction,faster electro-optic response relaxation,higher optical damage threshold,wider transparency window,and lower birefringence compared with lithium niobate.Here,we developed an ultralow-loss lithium tantalate integrated photonic platform,including waveguides,grating couplers,and microring cavities.The measured highest optical Q factor of the microring cavities is beyond 10^(7),corresponding to the lowest waveguide propagation loss of~1.88 dB∕m.The photorefractive effect in such lithium tantalate microring cavities was experimentally demonstrated to be 500 times weaker than that in lithium niobate microcavities.This work lays the foundation for a lithium tantalate integrated platform for achieving a series of on-chip optically functional devices,such as periodically poled waveguides,acousto-optic modulators,and electro-optic modulators.展开更多
Electro-optic active metasurfaces have attracted attention due to their ability to electronically control optical wavefronts with unprecedented spatiotemporal resolutions.In most studies,such devices require gate arra...Electro-optic active metasurfaces have attracted attention due to their ability to electronically control optical wavefronts with unprecedented spatiotemporal resolutions.In most studies,such devices require gate arrays composed of a large number of independently-controllable local gate electrodes that address the local scattering response of individual metaatoms.Although this approach in principle enables arbitrary wavefront control,the complicated driving mechanism and low optical efficiency have been hindering its practical applications.In this work,we demonstrate an active beam switching device that provides highly directional beam profiles and significant and uniform optical efficiencies across diffraction orders separated by a large deflection angle.The device operates with only a single-gate bias applied to monolayer graphene,modulating its optical conductivity to control the optical efficiency of the device.The key performance metrics,the absolute and the relative efficiency,which are defined as the scattered power toward a certain angleθnormalized by the incident power and the net scattered power from the metasurface,respectively,are maximized by a genetic algorithm.Experimentally,the metasurface achieves 57°of active beam switching from the 0th to the−1st order diffraction,with absolute efficiencies of 0.084 and 0.078 and relative efficiencies of 0.765 and 0.836,respectively.Furthermore,an analytical framework using nonlocal quasinormal mode expansion provides deeper insight into the operating mechanism of active beam switching.Finally,we discuss the performance limitations of this design platform and provide insights into potential improvements.展开更多
Electro-optic active metasurfaces have attracted attention due to their ability to electronically control optical wavefronts with unprecedented spatiotemporal resolutions.In most studies,such devices require gate arra...Electro-optic active metasurfaces have attracted attention due to their ability to electronically control optical wavefronts with unprecedented spatiotemporal resolutions.In most studies,such devices require gate arrays composed of a large number of independently-controllable local gate electrodes that address the local scattering response of individual metaatoms.Although this approach in principle enables arbitrary wavefront control,the complicated driving mechanism and low optical efficiency have been hindering its practical applications.In this work,we demonstrate an active beam switching device that provides highly directional beam profiles and significant and uniform optical efficiencies across diffraction orders separated by a large deflection angle.The device operates with only a single-gate bias applied to monolayer graphene,modulating its optical conductivity to control the optical efficiency of the device.The key performance metrics,the absolute and the relative efficiency,which are defined as the scattered power toward a certain angleθnormalized by the incident power and the net scattered power from the metasurface,respectively,are maximized by a genetic algorithm.Experimentally,the metasurface achieves 57°of active beam switching from the 0th to the−1st order diffraction,with absolute efficiencies of 0.084 and 0.078 and relative efficiencies of 0.765 and 0.836,respectively.Furthermore,an analytical framework using nonlocal quasinormal mode expansion provides deeper insight into the operating mechanism of active beam switching.Finally,we discuss the performance limitations of this design platform and provide insights into potential improvements.展开更多
Proceeding from the consideration of the demands from the functional architecture of high speed, high capacity optical communication network, this paper points out that photonic integrated devices, including high spee...Proceeding from the consideration of the demands from the functional architecture of high speed, high capacity optical communication network, this paper points out that photonic integrated devices, including high speed response laser source, narrow band response photodetector high speed wavelength converter, dense wavelength multi/demultiplexer, low loss high speed response photo-switch and multi-beam coupler are the key components in the system. The investigation progress in the laboratory will be introduced.展开更多
Massive machine-type communications(mMTC)is envisioned to be one of the pivotal scenarios in the fifth-generation(5G)wireless communication,where the explosively emerging Internet-of-Things(IoT)applications have trigg...Massive machine-type communications(mMTC)is envisioned to be one of the pivotal scenarios in the fifth-generation(5G)wireless communication,where the explosively emerging Internet-of-Things(IoT)applications have triggered the demand for services with low-latency and high-reliability.To this end,grant-free random access paradigm has been proposed as a promising enabler in simplifying the connection procedure and significantly reducing access latency.In this paper,we propose to leverage the burgeoning reconfigurable intelligent surface(RIS)for grant-free massive access working at millimeter-wave(mmWave)frequency to further boost access reliability.By attaching independently controllable phase shifts,reconfiguring,and refracting the propagation of incident electromagnetic waves,the deployed RISs could provide additional diversity gain and enhance the access channel conditions.On this basis,to address the challenging active device detection(ADD)and channel estimation(CE)problem,we develop a joint-ADDCE(JADDCE)method by resorting to the existing approximate message passing(AMP)algorithm with expectation maximization(EM)to extract the structured common sparsity in traffic behaviors and cascaded channel matrices.Finally,simulations are carried out to demonstrate the superiority of our proposed scheme.展开更多
基金The Fundamental Research Funds for the Central Universities(JD2423)。
文摘Pump valve pipeline vibration brings serious safety hazards to the operation of the equipment,for the pump valve system in the process of variable flow,variable speed,variable openings lead to excessive pipeline vibration.An active damping device(ADD)is used to the vibration of the pump valve pipeline system to apply the control force,to achieve the active control of the pipeline vibration.A pump-valve pipeline vibration test bench was built to compare the control effect of active damping device on pipeline vibration under different pump valve working conditions,and the results show that applying ADD control could effectively suppress the vibration of the pump valve pipeline and enhance the stability of the equipment during operation.At different pump operating rotation frequencies,the vibration amplitude of the pump valve pipeline in working frequency and its multiple frequencies are also effectively suppressed,with the maximum amplitude reduction of more than 60%.For the valve vibration caused by different operating openings,the vibration of the highest reduction of 68%,and the centrifugal pump drive shaft vi-bration reduced by up to 73%,which provides a new idea for vibration control of pump valve pipeline system.
文摘A simplified simulation method based on the FDTD technique that can handle active devices is proposed. This method well suits the electrical crosstalk analysis of multi-channel integrated, opto-electronic mixed modules. We apply this method to an 8-channel integrated super-compact high-sensitivity optical module. The results show good agreement between simulations and measurements.
基金The work is supported in part by the National Natural Science Foundation of China(Grant Nos.62171483,82061148011)Zhejiang Provincial Natural Science Foundation of China(Grant No.LZ23F010004)+1 种基金Hangzhou Agricultural and Social Development Research Key Project(Grant No.20231203A08)Doctoral Initiation Program of the Tenth Affiliated Hospital,Southern Medical University(Grant No.K202308).
文摘The development of precise and sensitive electrophysiological recording platforms holds the utmost importance for research in the fields of cardiology and neuroscience.In recent years,active micro/nano-bioelectronic devices have undergone significant advancements,thereby facilitating the study of electrophysiology.The distinctive configuration and exceptional functionality of these active micro-nano-collaborative bioelectronic devices offer the potential for the recording of high-fidelity action potential signals on a large scale.In this paper,we review three-dimensional active nano-transistors and planar active micro-transistors in terms of their applications in electroexcitable cells,focusing on the evaluation of the effects of active micro/nano-bioelectronic devices on electrophysiological signals.Looking forward to the possibilities,challenges,and wide prospects of active micro-nano-devices,we expect to advance their progress to satisfy the demands of theoretical investigations and medical implementations within the domains of cardiology and neuroscience research.
基金Project supported by the National Natural Science Foundation of China(Grant No.61675041)the National Science Funds for Creative Research Groups of China(Grant No.61421002)
文摘Organic optoelectronic integrated devices（OIDs） with ultraviolet（UV） photodetectivity and different color emitting were constructed by using a thermally activated delayed fluorescence（TADF） material 4, 5-bis（carbazol-9-yl）-1, 2-dicyanobenzene（2 CzPN） as host. The OIDs doping with typical red phosphorescent dye [tris（1-phenylisoquinoline）iridium（Ⅲ）, Ir（piq）3], orange phosphorescent dye {bis[2-（4-tertbutylphenyl）benzothiazolato-N,C-（2＇）]iridium（acetylacetonate）,（tbt）2 Ir（acac）}, and blue phosphorescent dye [bis（2, 4-di-fluorophenylpyridinato）-tetrakis（1-pyrazolyl）borate iridium（Ⅲ）, FIr6] were investigated and compared. The（tbt）2 Ir（acac）-doped orange device showed better performance than those of red and blue devices, which was ascribed to more effective energy transfer. Meanwhile, at a low dopant concentration of 3 wt.%, the（tbt）2 Ir（acac）-doped OIDs showed the maximum luminance, current efficiency, power efficiency of 70786 cd/m^2, 39.55 cd/A, and 23.92 lm/W, respectively, and a decent detectivity of 1.07 × 10^11 Jones at a bias of -2 V under the UV-350 nm illumination. This work may arouse widespread interest in constructing high efficiency and luminance OIDs based on doping phosphorescent dye.
基金supported by the National Natural Science Foundation of China under Grant No.61131005Keygrant Project of Chinese Ministry of Education under Grant No.313013+1 种基金New Century Excellent Talent Foundation under Grant No.NCET-11-0068Sichuan Youth S.&T.Foundation under Grant No.2011JQ0001
文摘Vanadium dioxide （VO2） is a phase transition material which undergoes a reversible metal-insulator transition （MIT） when triggered by thermal, photo, electrical, and even stress. The huge conduction change of VO2 renders it a promising material for terahertz （THz） manipulation. In this paper, some interesting works concerning the growth and characteristics of the VO2 film are selectively reviewed. A switching of THz radiation by photo-driven VO2 film is demonstrated. Experiments indicate an ultrafast optical switching to THz transmission within 8 picoseconds, and a switching ratio reaches to over 80%during a wide frequency range from 0.3 THz to 2.5 THz.
文摘Given the interdisciplinary challenges in materials sciences, chemistry, physics, and biology, as well as the demands to merge electronics and photonics at the nanometer scale for miniaturized integrated circuits, plasmonics serves as a bridge by breaking the limit in the speed of nanoscale electronics and the size of terahertz dielectric photonics. Active plasmonic systems enabling active control over the plasmonic properties in real time have opened up a wealth of potential applications. This review focuses on the development of active plasmonic response devices. Significant advances have been achieved in control over the dielectric properties of the active surrounding medium, including liquid crystals, polymers, photochromic molecules and inorganic materials, which in turn allows tuning of the reversible plasmon resonance switch of neighboring metal nanostructures.
基金the National Research Foundation of Korea(NRF)grant funded by theKoreaGovernment(MSIT)(No.2021R1C1C1013133)Basic ScienceResearch Programthrough the NationalResearch Foundation ofKorea(NRF)funded by the Ministry of Education(NRF-2020R1I1A3066543)the Soonchunhyang University Research Fund.
文摘Networks based on backscatter communication provide wireless data transmission in the absence of a power source.A backscatter device receives a radio frequency(RF)source and creates a backscattered signal that delivers data;this enables new services in battery-less domains with massive Internet-of-Things(IoT)devices.Connectivity is highly energy-efficient in the context of massive IoT applications.Outdoors,long-range(LoRa)backscattering facilitates large IoT services.A backscatter network guarantees timeslot-and contention-based transmission.Timeslot-based transmission ensures data transmission,but is not scalable to different numbers of transmission devices.If contention-based transmission is used,collisions are unavoidable.To reduce collisions and increase transmission efficiency,the number of devices transmitting data must be controlled.To control device activation,the RF source range can be modulated by adjusting the RF source power during LoRa backscatter.This reduces the number of transmitting devices,and thus collisions and retransmission,thereby improving transmission efficiency.We performed extensive simulations to evaluate the performance of our method.
基金Supported by National Table Poultry Industry Technology System ItemChina(CARS-42-G21)+1 种基金Technique Innovation Item of Jinan Colleges and AcademiesChina(201302053)
文摘In accordance with current problems such as odor pollution,long production period,consumption of a large amount of manpower and so on existing in chicken manure fermentation ,an environment friendly type of chicken manure fermentation device is designed. The key parameters of the equipment are resonance activated tube and fermenting cellar. Resonance activated tube makes the activated water,which could improve obvi- ously the biodegradation rate of chicken manure. The aerator could provide enough oxygen to microbes,and the agitator could make oxygen evenly distributed across the chicken manure in fermenting cellar. The test shows that this equipment is high-efficiency,and only takes 7 days to make the chicken manure achieve the decomposed requirement. The organic matter content of composted chicken manure is 91.2%,C/N ratio is 18.8, MPN is 0.04, mortality of ascarid egg is 99.6% ,concentrations of NH3 and H2 S are 4.20 and 1.58 mg/m3, furthermore ,there is no offensive smell in the fermenting cellar. Therefore,the study can provide a pollution-free, high-efficiency, manpower saving fermentation equipment for organic fertilizer production by chicken manure in agriculture area.
基金the National Natural Science Foundation of China(Grant No.11104200)the Natural Science Foundation of Tianjin(No.18JCYBJC17000).
文摘Electromagnetically induced transparency(EIT)phenomenon is observed in simple metamaterial which consists of concentric double U-shaped resonators(USRs).The numerical and theoretical analysis reveals that EIT arises from the bright-bright mode coupling.The transmission spectra at different polarization angle of incident light shows that EIT transparency window is polarization sensitive.More interestingly,Fano resonance appears in the transmission spectrum at certain polarization angles.The sharp and asymmetric Fano lineshape is high valuable for sensing.The performance of sensor is investigated and the sensitivity is high up to 327 GHz/RIU.Furthermore,active control of EIT window is realized by incorporating photosensitive silicon.The proposed USR structure is simple and compact,which may find significant applications in tunable integrated devices such as biosensor,filters,and THz modulators.
基金support from National Key R&D Program of China(2022YFA1404604)Chinese Academy of Sciences Project for Young Scientists in Basic Research(No.YSBR-112),Science and Technology Commission of Shanghai Municipality(16ZR1442600,20JC1416200)+6 种基金National Natural Science Foundation of China(Nos.12074400,U1732268,62293521,61874128,61851406,11774326 and 11705262)the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDB0670303)Shanghai Science and Technology Innovation Action Plan Program(20JC1416200,22JC1403300)Frontier Science Key Program of Chinese Academy of Sciences(No.QYZDY-SSW-JSC032),Innovation Program for Quantum Science and Technology(No.2021ZD0300204)Shanghai Municipal Science and Technology Major Project(No.2019SHZDZX01)Autonomous deployment project of State Key Laboratory of Materials for Integrated Circuits(No.SKLJCZ2024-B03)State Key Laboratory of Advanced Optical Communication Systems and Networks(No.2024GZKF11).
文摘The ability to control nonclassical light emission from a single quantum emitter by an integrated cavity may unleash new perspectives for integrated photonic quantum applications.However,coupling a single quantum emitter to cavity within photonic circuitry towards creation of the Purcell-enhanced single-photon emission is elusive due to the complexity of integrating active devices in low-loss photonic circuits.Here we demonstrate a hybrid micro-ring resonator(HMRR)coupled with self-assembled quantum dots(QDs)for cavity-enhanced deterministic single-photon emission.The HMRR cavity supports whispering-gallery modes with quality factors up to 7.8×103.By further introducing a micro-heater,we show that the photon emission of QDs can be locally and dynamically tuned over one free spectral ranges of the HMRR(~4 nm).This allows precise tuning of individual QDs in resonance with the cavity modes,thereby enhancing single-photon emission with a Purcell factor of about 4.9.Our results on the hybrid integrated cavities coupled with two-level quantum emitters emerge as promising devices for chip-based scalable photonic quantum applications.
基金Research Grants Council of Hong Kong(C4050-21E,RFS2324-4S03,14203623)The Chinese University of Hong Kong(Group Research Scheme)。
文摘Thin-film lithium niobate has attracted great interest in high-speed communication due to its unique piezoelectric and nonlinear properties.However,its high photorefraction and slow electro-optic response relaxation introduce the possibility of transmission bit errors.Recently,lithium tantalate,another piezoelectric and nonlinear material,has emerged as a promising candidate for active photonic integrated devices because of its weaker photorefraction,faster electro-optic response relaxation,higher optical damage threshold,wider transparency window,and lower birefringence compared with lithium niobate.Here,we developed an ultralow-loss lithium tantalate integrated photonic platform,including waveguides,grating couplers,and microring cavities.The measured highest optical Q factor of the microring cavities is beyond 10^(7),corresponding to the lowest waveguide propagation loss of~1.88 dB∕m.The photorefractive effect in such lithium tantalate microring cavities was experimentally demonstrated to be 500 times weaker than that in lithium niobate microcavities.This work lays the foundation for a lithium tantalate integrated platform for achieving a series of on-chip optically functional devices,such as periodically poled waveguides,acousto-optic modulators,and electro-optic modulators.
基金supported by the National Research Foundation of Korea(NRF)grants(NRF-2022R1A2C2092095,RS-2024-00416583,RS-2024-00414119,RS-2024-00452558)funded by the Korea government(MSIT)Samsung Research Funding and Incubation Center of Samsung Electronics grant(SRFC-IT1702-14)+1 种基金This research was also supported by the Ministry of Trade,Industry&Energy(MOTIE)(1415180303)the Korea Semiconductor Research Consortium(KSRC)(20019357).
文摘Electro-optic active metasurfaces have attracted attention due to their ability to electronically control optical wavefronts with unprecedented spatiotemporal resolutions.In most studies,such devices require gate arrays composed of a large number of independently-controllable local gate electrodes that address the local scattering response of individual metaatoms.Although this approach in principle enables arbitrary wavefront control,the complicated driving mechanism and low optical efficiency have been hindering its practical applications.In this work,we demonstrate an active beam switching device that provides highly directional beam profiles and significant and uniform optical efficiencies across diffraction orders separated by a large deflection angle.The device operates with only a single-gate bias applied to monolayer graphene,modulating its optical conductivity to control the optical efficiency of the device.The key performance metrics,the absolute and the relative efficiency,which are defined as the scattered power toward a certain angleθnormalized by the incident power and the net scattered power from the metasurface,respectively,are maximized by a genetic algorithm.Experimentally,the metasurface achieves 57°of active beam switching from the 0th to the−1st order diffraction,with absolute efficiencies of 0.084 and 0.078 and relative efficiencies of 0.765 and 0.836,respectively.Furthermore,an analytical framework using nonlocal quasinormal mode expansion provides deeper insight into the operating mechanism of active beam switching.Finally,we discuss the performance limitations of this design platform and provide insights into potential improvements.
基金supported by the National Research Foundation of Korea(NRF)grants(NRF-2022R1A2C2092095,RS-2024-00416583,RS-2024-00414119,RS2024-00452558)funded by the Korea government(MSIT),and Samsung Research Funding and Incubation Center of Samsung Electronics grant(SRFCIT1702-14)+1 种基金supported by the Ministry of Trade,Industry&Energy(MOTIE)(1415180303)the Korea Semiconductor Research Consortium(KSRC)(20019357).
文摘Electro-optic active metasurfaces have attracted attention due to their ability to electronically control optical wavefronts with unprecedented spatiotemporal resolutions.In most studies,such devices require gate arrays composed of a large number of independently-controllable local gate electrodes that address the local scattering response of individual metaatoms.Although this approach in principle enables arbitrary wavefront control,the complicated driving mechanism and low optical efficiency have been hindering its practical applications.In this work,we demonstrate an active beam switching device that provides highly directional beam profiles and significant and uniform optical efficiencies across diffraction orders separated by a large deflection angle.The device operates with only a single-gate bias applied to monolayer graphene,modulating its optical conductivity to control the optical efficiency of the device.The key performance metrics,the absolute and the relative efficiency,which are defined as the scattered power toward a certain angleθnormalized by the incident power and the net scattered power from the metasurface,respectively,are maximized by a genetic algorithm.Experimentally,the metasurface achieves 57°of active beam switching from the 0th to the−1st order diffraction,with absolute efficiencies of 0.084 and 0.078 and relative efficiencies of 0.765 and 0.836,respectively.Furthermore,an analytical framework using nonlocal quasinormal mode expansion provides deeper insight into the operating mechanism of active beam switching.Finally,we discuss the performance limitations of this design platform and provide insights into potential improvements.
基金This work was supported by the National Natural Science Foundation of China (Grant No. 69896260) the Major State Basic Research program under Grant No. 2000036601-605.
文摘Proceeding from the consideration of the demands from the functional architecture of high speed, high capacity optical communication network, this paper points out that photonic integrated devices, including high speed response laser source, narrow band response photodetector high speed wavelength converter, dense wavelength multi/demultiplexer, low loss high speed response photo-switch and multi-beam coupler are the key components in the system. The investigation progress in the laboratory will be introduced.
基金supported by the National Natural Science Foundation of China(NSFC)(No.62071044)the Open Research Fund of National Mobile Communications Research Laboratory,Southeast University(No.2022D09)+1 种基金Beijing Institute of Technology Research Fund Program for Young Scholars(No.XSQD-202121009)Ensan Foundation(No.2022006).
文摘Massive machine-type communications(mMTC)is envisioned to be one of the pivotal scenarios in the fifth-generation(5G)wireless communication,where the explosively emerging Internet-of-Things(IoT)applications have triggered the demand for services with low-latency and high-reliability.To this end,grant-free random access paradigm has been proposed as a promising enabler in simplifying the connection procedure and significantly reducing access latency.In this paper,we propose to leverage the burgeoning reconfigurable intelligent surface(RIS)for grant-free massive access working at millimeter-wave(mmWave)frequency to further boost access reliability.By attaching independently controllable phase shifts,reconfiguring,and refracting the propagation of incident electromagnetic waves,the deployed RISs could provide additional diversity gain and enhance the access channel conditions.On this basis,to address the challenging active device detection(ADD)and channel estimation(CE)problem,we develop a joint-ADDCE(JADDCE)method by resorting to the existing approximate message passing(AMP)algorithm with expectation maximization(EM)to extract the structured common sparsity in traffic behaviors and cascaded channel matrices.Finally,simulations are carried out to demonstrate the superiority of our proposed scheme.
