A new on-chip light source configuration has been proposed,which utilizes the interaction between a microwave or laser and a dielectric nanopillar array to generate a periodic electromagnetic near-field and applies pe...A new on-chip light source configuration has been proposed,which utilizes the interaction between a microwave or laser and a dielectric nanopillar array to generate a periodic electromagnetic near-field and applies periodic transverse acceleration to relativistic electrons to generate high-energy photon radiation.The dielectric nanopillar array interacting with the driving field acts as an electron undulator,in which the near-field drives electrons to oscillate.When an electron beam propagates through this nanopillar array in this light source configuration,it is subjected to a periodic transverse near-field force and will radiate X-ray or evenγ-ray high-energy photons after a relativistic frequency up-conversion.Compared with the undulator which is based on the interaction between strong lasers and nanostructures to generate a plasmonic near-field,this configuration is less prone to damage during operation.展开更多
Power Line Communications-Artificial Intelligence of Things(PLC-AIo T)combines the low cost and high coverage of PLC with the learning ability of Artificial Intelligence(AI)to provide data collection and transmission ...Power Line Communications-Artificial Intelligence of Things(PLC-AIo T)combines the low cost and high coverage of PLC with the learning ability of Artificial Intelligence(AI)to provide data collection and transmission capabilities for PLC-AIo T devices in smart parks.With the development of smart parks,their emerging services require secure and accurate time synchronization of PLC-AIo T devices.However,the impact of attackers on the accuracy of time synchronization cannot be ignored.To solve the aforementioned problems,we propose a tampering attack-aware Deep Q-Network(DQN)-based time synchronization algorithm.First,we construct an abnormal clock source detection model.Then,the abnormal clock source is detected and excluded by comparing the time synchronization information between the device and the gateway.Finally,the proposed algorithm realizes the joint guarantee of high accuracy and low delay for PLC-AIo T in smart parks by intelligently selecting the multi-clock source cooperation strategy and timing weights.Simulation results show that the proposed algorithm has better time synchronization delay and accuracy performance.展开更多
Serving as the electrical to optical converter,the on-chip silicon light source is an indispensable component of silicon photonic technologies and has long been pursued.Here,we briefly review the history and recent pr...Serving as the electrical to optical converter,the on-chip silicon light source is an indispensable component of silicon photonic technologies and has long been pursued.Here,we briefly review the history and recent progress of a few promising contenders for on-chip light sources in terms of operating wavelength,pump condition,power consumption,and fabrication process.Additionally,the performance of each contender is also assessed with respect to thermal stability,which is a crucial parameter to consider in complex optoelectronic integrated circuits(OEICs)and optical interconnections.Currently,III-V-based silicon(Si)lasers formed via bonding techniques demonstrate the best performance and display the best opportunity for commercial usage in the near future.However,in the long term,direct hetero-epitaxial growth of III–V materials on Si seems more promising for low-cost,high-yield fabrication.The demonstration of high-performance quantum dot(QD)lasers monolithically grown on Si strongly forecasts its feasibility and enormous potential for on-chip lasers.The superior temperature-insensitive characteristics of the QD laser promote this design in large-scale high-density OEICs.The Germanium(Ge)-on-Si laser is also competitive for large-scale monolithic integration in the future.Compared with a III-V-based Si laser,the biggest potential advantage of a Ge-on-Si laser lies in its material and processing compatibility with Si technology.Additionally,the versatility of Ge facilitates photon emission,modulation,and detection simultaneously with a simple process complexity and low cost.展开更多
Objective HEPS is a fourth-generation photon source under construction.HEPS adopts the magnetic focusing structure of 7BA,and the beam dynamics aperture is very small.HEPS injection scheme adopts the on-axis injection...Objective HEPS is a fourth-generation photon source under construction.HEPS adopts the magnetic focusing structure of 7BA,and the beam dynamics aperture is very small.HEPS injection scheme adopts the on-axis injection scheme.To minimize perturbation on adjacent bunches during on-axis swap out injection,a set of superfast kicker and high-voltage fast pulse power supply are needed.The high-voltage fast pulse power supply uses pulsed power stacking technologies,and the power supply needs the multichannel and low jitter clock signal.Therefore,it is necessary to develop a precise clock source.Method The clock source adopts FPGA controller with full digital control,and the output pulse mode of the system can be adjusted in real time.A detection module based on program control is used to check repetition rate and bottom width of input clock and output clock in real time.High-speed and precision clock signal output circuit is used to guarantee signal integrity and reduce clock signal jitter.Conclusion The prototype experiment proves that the output clock can well meet requirements of design.The minimum bottom width of the independent clock is 5 ns,the minimum time interval of the two groups of clocks is 5 ns,and the jitter of output clock is lower than 50 ps.The developed clock source can well meet the application requirements of high-voltage fast pulse power supply in HEPS injection system.展开更多
基金pported by the National Natural Science Foundation of China(Grant Nos.12325409,12388102,12074398,and U2267204)the CAS Project for Young Scientists in Basic Research(Grant No.YSBR-060)the Shanghai Pilot Program for Basic Research,Chinese Academy of Sciences Shanghai Branch。
文摘A new on-chip light source configuration has been proposed,which utilizes the interaction between a microwave or laser and a dielectric nanopillar array to generate a periodic electromagnetic near-field and applies periodic transverse acceleration to relativistic electrons to generate high-energy photon radiation.The dielectric nanopillar array interacting with the driving field acts as an electron undulator,in which the near-field drives electrons to oscillate.When an electron beam propagates through this nanopillar array in this light source configuration,it is subjected to a periodic transverse near-field force and will radiate X-ray or evenγ-ray high-energy photons after a relativistic frequency up-conversion.Compared with the undulator which is based on the interaction between strong lasers and nanostructures to generate a plasmonic near-field,this configuration is less prone to damage during operation.
基金supported by the Science and Technology Project of the State Grid Corporation of China under Grant Number 5400202199541A-0-5-ZN。
文摘Power Line Communications-Artificial Intelligence of Things(PLC-AIo T)combines the low cost and high coverage of PLC with the learning ability of Artificial Intelligence(AI)to provide data collection and transmission capabilities for PLC-AIo T devices in smart parks.With the development of smart parks,their emerging services require secure and accurate time synchronization of PLC-AIo T devices.However,the impact of attackers on the accuracy of time synchronization cannot be ignored.To solve the aforementioned problems,we propose a tampering attack-aware Deep Q-Network(DQN)-based time synchronization algorithm.First,we construct an abnormal clock source detection model.Then,the abnormal clock source is detected and excluded by comparing the time synchronization information between the device and the gateway.Finally,the proposed algorithm realizes the joint guarantee of high accuracy and low delay for PLC-AIo T in smart parks by intelligently selecting the multi-clock source cooperation strategy and timing weights.Simulation results show that the proposed algorithm has better time synchronization delay and accuracy performance.
基金This work was partially supported by the Major International Cooperation and Exchange Program of the National Natural Science Foundation of China under Grant 61120106012the Peking University 985 Startup Fund.
文摘Serving as the electrical to optical converter,the on-chip silicon light source is an indispensable component of silicon photonic technologies and has long been pursued.Here,we briefly review the history and recent progress of a few promising contenders for on-chip light sources in terms of operating wavelength,pump condition,power consumption,and fabrication process.Additionally,the performance of each contender is also assessed with respect to thermal stability,which is a crucial parameter to consider in complex optoelectronic integrated circuits(OEICs)and optical interconnections.Currently,III-V-based silicon(Si)lasers formed via bonding techniques demonstrate the best performance and display the best opportunity for commercial usage in the near future.However,in the long term,direct hetero-epitaxial growth of III–V materials on Si seems more promising for low-cost,high-yield fabrication.The demonstration of high-performance quantum dot(QD)lasers monolithically grown on Si strongly forecasts its feasibility and enormous potential for on-chip lasers.The superior temperature-insensitive characteristics of the QD laser promote this design in large-scale high-density OEICs.The Germanium(Ge)-on-Si laser is also competitive for large-scale monolithic integration in the future.Compared with a III-V-based Si laser,the biggest potential advantage of a Ge-on-Si laser lies in its material and processing compatibility with Si technology.Additionally,the versatility of Ge facilitates photon emission,modulation,and detection simultaneously with a simple process complexity and low cost.
文摘Objective HEPS is a fourth-generation photon source under construction.HEPS adopts the magnetic focusing structure of 7BA,and the beam dynamics aperture is very small.HEPS injection scheme adopts the on-axis injection scheme.To minimize perturbation on adjacent bunches during on-axis swap out injection,a set of superfast kicker and high-voltage fast pulse power supply are needed.The high-voltage fast pulse power supply uses pulsed power stacking technologies,and the power supply needs the multichannel and low jitter clock signal.Therefore,it is necessary to develop a precise clock source.Method The clock source adopts FPGA controller with full digital control,and the output pulse mode of the system can be adjusted in real time.A detection module based on program control is used to check repetition rate and bottom width of input clock and output clock in real time.High-speed and precision clock signal output circuit is used to guarantee signal integrity and reduce clock signal jitter.Conclusion The prototype experiment proves that the output clock can well meet requirements of design.The minimum bottom width of the independent clock is 5 ns,the minimum time interval of the two groups of clocks is 5 ns,and the jitter of output clock is lower than 50 ps.The developed clock source can well meet the application requirements of high-voltage fast pulse power supply in HEPS injection system.
