Break junctions are important in generating nanosensors and single molecular devices. The mechanically con- trollable break junction is the most widely used method for a break junction due to its simplicity and stabil...Break junctions are important in generating nanosensors and single molecular devices. The mechanically con- trollable break junction is the most widely used method for a break junction due to its simplicity and stability. However, the bandwidths of traditional devices are limited to about a few hertz. Moreover, when using traditional methods it is hard to allow independent control of more than one junction. Here we propose on-chip thermally controllable break junctions to overcome these challenges. This is verified by using finite element analysis. Adopting microelectromechanical systems produces features of high bandwidth and independent controllability to this new break junction system. The proposed method will have a wide range of applications on on-chip high speed independent controllable and highly integrated single molecule devices.展开更多
Background Fourth-generation photon sources like Free Electron Lasers(FEL)and Diffraction-Limited Storage Rings(DLSR)have high requirements for beam emittance.In the case of DLSR sources,a set of high-performance fast...Background Fourth-generation photon sources like Free Electron Lasers(FEL)and Diffraction-Limited Storage Rings(DLSR)have high requirements for beam emittance.In the case of DLSR sources,a set of high-performance fast orbit feedback system(FOFB)is needed to correct the beam orbit quickly and accurately.Purpose FOFB system has four key components,which is BPM,orbit feedback calculation,fast correction magnet and fast corrector power supply.The FOFB gives the correction command and controls the fast corrector power supply to drive the fast correction magnet to correct the beam quickly and accurately.The corrector power supply has an important impact on the performance of FOFB.The corrector power supply needs to have high bandwidth and low output current ripple.Methods The new GaN power device is used to solve the restriction of the high-speed switching.The switching frequency of the power supply is increased to 300 kHz.The control system is designed to improve the bandwidth and optimize the output current ripple.The modeling analysis of the key parts of the system is given and the simulation experiments are carried out with MATLAB.Results and conclusion The test results showed that bandwidth of the designed power supply is 20 kHz.The step response time is 18us and output current ripple is lower than 1 mA.展开更多
A backside illuminated mesa-structure In Ga As/In P modified uni-traveling-carrier photodiode（MUTC-PD） with wide bandwidth and high saturation power is fabricated and investigated. The device structure is optimized ...A backside illuminated mesa-structure In Ga As/In P modified uni-traveling-carrier photodiode（MUTC-PD） with wide bandwidth and high saturation power is fabricated and investigated. The device structure is optimized to reduce the capacitance and resistance. For the 22-μm-diameter device, the maximum responsivity at 1.55 μm is 0.5 A/W, and the 3-d B cutoff frequency reaches up to 28 GHz. The output photocurrent at the 1-d B compression point is measured to be 54 m A at 25 GHz, with a corresponding output radio frequency（RF） power of up to 15.5 d Bm. The saturation characteristics of the MUTC-PD are also verified by the electric field simulation, and electric field collapse is found to be the cause of the saturation phenomenon.展开更多
光传送网(Optical Transport Network,OTN)技术凭借其独特的优势,在智能电网通信领域得到了广泛应用。深入探讨OTN技术在智能电网通信中的应用,详细阐述OTN技术的基本原理、对智能电网通信需求的适配情况、关键应用,分析其面临的挑战并...光传送网(Optical Transport Network,OTN)技术凭借其独特的优势,在智能电网通信领域得到了广泛应用。深入探讨OTN技术在智能电网通信中的应用,详细阐述OTN技术的基本原理、对智能电网通信需求的适配情况、关键应用,分析其面临的挑战并提出相应解决方案,为进一步提高智能电网通信水平提供理论依据和实践指导。展开更多
基金Supported by the National Key Basic Research Program of China under Grant No 2013CB921800the National Natural Science Foundation of China under Grant Nos 11227901,91021005,11274299,11104262 and 10834005the Strategic Priority Research Program(B)of the Chinese Academy of Sciences under Grant No XDB01030400
文摘Break junctions are important in generating nanosensors and single molecular devices. The mechanically con- trollable break junction is the most widely used method for a break junction due to its simplicity and stability. However, the bandwidths of traditional devices are limited to about a few hertz. Moreover, when using traditional methods it is hard to allow independent control of more than one junction. Here we propose on-chip thermally controllable break junctions to overcome these challenges. This is verified by using finite element analysis. Adopting microelectromechanical systems produces features of high bandwidth and independent controllability to this new break junction system. The proposed method will have a wide range of applications on on-chip high speed independent controllable and highly integrated single molecule devices.
文摘Background Fourth-generation photon sources like Free Electron Lasers(FEL)and Diffraction-Limited Storage Rings(DLSR)have high requirements for beam emittance.In the case of DLSR sources,a set of high-performance fast orbit feedback system(FOFB)is needed to correct the beam orbit quickly and accurately.Purpose FOFB system has four key components,which is BPM,orbit feedback calculation,fast correction magnet and fast corrector power supply.The FOFB gives the correction command and controls the fast corrector power supply to drive the fast correction magnet to correct the beam quickly and accurately.The corrector power supply has an important impact on the performance of FOFB.The corrector power supply needs to have high bandwidth and low output current ripple.Methods The new GaN power device is used to solve the restriction of the high-speed switching.The switching frequency of the power supply is increased to 300 kHz.The control system is designed to improve the bandwidth and optimize the output current ripple.The modeling analysis of the key parts of the system is given and the simulation experiments are carried out with MATLAB.Results and conclusion The test results showed that bandwidth of the designed power supply is 20 kHz.The step response time is 18us and output current ripple is lower than 1 mA.
基金Project supported by the National Basic Research Program of China(Grant Nos.2012CB315605 and 2014CB340002)the National Natural Science Foundation of China(Grant Nos.61176015,61176059,61210014,61321004,and 61307024)the Open Fund of State Key Laboratory on Integrated Optoelectronics,China(Grant Nos.IOSKL2012KF08 and IOSKL2014KF09)
文摘A backside illuminated mesa-structure In Ga As/In P modified uni-traveling-carrier photodiode（MUTC-PD） with wide bandwidth and high saturation power is fabricated and investigated. The device structure is optimized to reduce the capacitance and resistance. For the 22-μm-diameter device, the maximum responsivity at 1.55 μm is 0.5 A/W, and the 3-d B cutoff frequency reaches up to 28 GHz. The output photocurrent at the 1-d B compression point is measured to be 54 m A at 25 GHz, with a corresponding output radio frequency（RF） power of up to 15.5 d Bm. The saturation characteristics of the MUTC-PD are also verified by the electric field simulation, and electric field collapse is found to be the cause of the saturation phenomenon.
文摘光传送网(Optical Transport Network,OTN)技术凭借其独特的优势,在智能电网通信领域得到了广泛应用。深入探讨OTN技术在智能电网通信中的应用,详细阐述OTN技术的基本原理、对智能电网通信需求的适配情况、关键应用,分析其面临的挑战并提出相应解决方案,为进一步提高智能电网通信水平提供理论依据和实践指导。
