A Data Acquisition System （DAQ） for electron energy loss coincident spectrometers （EELCS） has been developed. The system is composed of a Multiplex Time-Digital Converter （TDC） that measures the flying time of p...A Data Acquisition System （DAQ） for electron energy loss coincident spectrometers （EELCS） has been developed. The system is composed of a Multiplex Time-Digital Converter （TDC） that measures the flying time of positive and negative ions and a one-dimension positionsensitive detector that records the energy loss of scattering electrons. The experimental data are buffered in a first-in-first-out（FIFO） memory module, then transferred from the FIFO memory to PC by the USB interface. The DAQ system can record the flying time of several ions in one collision, and allows of different data collection modes. The system has been demonstrated at the Electron Energy Loss Coincident Spectrometers at the Laboratory of Atomic and Molecular Physics, USTC. A detail description of the whole system is given and experimental results shown.展开更多
An In P-based monolithically integrated few-mode transmitter aiming at the combination of wavelength division multiplexing（WDM） and mode division multiplexing（MDM） technologies is proposed. The core elements of th...An In P-based monolithically integrated few-mode transmitter aiming at the combination of wavelength division multiplexing（WDM） and mode division multiplexing（MDM） technologies is proposed. The core elements of the proposed transmitter are mode converters and a wavelength-mode division multiplexer that are all based on multimode interference（MMI） couplers. Simulations show that the wavelength-mode division multiplexer has a large fabrication tolerance of 30 and 0.5 μm for the length and the width of the device, respectively.A low loss below 0.26 dB for the passive parts of the transmitter is obtained in the whole C-band wavelength range.展开更多
基金National Natural Science Foundation of China (Nos. 10134010 and 10004010)
文摘A Data Acquisition System （DAQ） for electron energy loss coincident spectrometers （EELCS） has been developed. The system is composed of a Multiplex Time-Digital Converter （TDC） that measures the flying time of positive and negative ions and a one-dimension positionsensitive detector that records the energy loss of scattering electrons. The experimental data are buffered in a first-in-first-out（FIFO） memory module, then transferred from the FIFO memory to PC by the USB interface. The DAQ system can record the flying time of several ions in one collision, and allows of different data collection modes. The system has been demonstrated at the Electron Energy Loss Coincident Spectrometers at the Laboratory of Atomic and Molecular Physics, USTC. A detail description of the whole system is given and experimental results shown.
基金supported by the National 973 Program of China(No.2014CB340102)the National Nature Science Foundation of China(Nos.61320106013 and61271066)
文摘An In P-based monolithically integrated few-mode transmitter aiming at the combination of wavelength division multiplexing（WDM） and mode division multiplexing（MDM） technologies is proposed. The core elements of the proposed transmitter are mode converters and a wavelength-mode division multiplexer that are all based on multimode interference（MMI） couplers. Simulations show that the wavelength-mode division multiplexer has a large fabrication tolerance of 30 and 0.5 μm for the length and the width of the device, respectively.A low loss below 0.26 dB for the passive parts of the transmitter is obtained in the whole C-band wavelength range.
