为了动态控制用于植物生长的人工光源，该文提出一种以光子数作为评价标准，使红蓝光比例连续可调的LED植物生长光源的配光方法。综合考虑红、蓝2种波段光源及其他光谱的作用，该文采用白光LED与红光LED 组合配比，以正向电流下 LED 的...为了动态控制用于植物生长的人工光源，该文提出一种以光子数作为评价标准，使红蓝光比例连续可调的LED植物生长光源的配光方法。综合考虑红、蓝2种波段光源及其他光谱的作用，该文采用白光LED与红光LED 组合配比，以正向电流下 LED 的光谱密度数据作为计算基础，提出配光设计算法，实现红蓝成分有效光子数维持一定的要求下，红光与蓝光光子数比在指定区间（4：1～9：1之间）连续可调，从而满足植物不同生长状态对光质成分的需要。展开更多
A new calibration method of detectors can be realized by using correlated photons generated in spontaneous parametric down-conversion （SPDC） effect of nonlinear crystal. An absolute calibration system of detector qu...A new calibration method of detectors can be realized by using correlated photons generated in spontaneous parametric down-conversion （SPDC） effect of nonlinear crystal. An absolute calibration system of detector quantum efficiency is performed. And its principle and experimental setup are introduced. A continuouswave （CW） ultraviolet （351 nm）, diode-pumped, frequency-doubled, and solid-state laser is used to pump BBO crystal. The quantum efficiencies of the photomultiplier at 633, 702, and 789 nm are measured respectively. The coincidence peaks are observed using coincidence circuit. Some measurement factors including the filter bandwidth of trigger channel, the detector position alignment and polarization of the pump light are analyzed. The uncertainties of this calibration method are also analyzed, and the relative uncertainties of total calibration are less than 5.8%. The accuracy of this method could be improved in the future.展开更多
QUANTIZED radiation fields exhibiting nonclassical properties have been of great theoretical andexperimental interest in the last two decades. It is shown that various nonclassical states suchas squeezed state and Sch...QUANTIZED radiation fields exhibiting nonclassical properties have been of great theoretical andexperimental interest in the last two decades. It is shown that various nonclassical states suchas squeezed state and Schrodinger cat state can be generated out of coherent state in thenonlinear process of the interaction of atom and field although the radiation field in a展开更多
In this paper a scheme for quantum secure direct communication （QSDC） network is proposed with a sequence of polarized single photons. The single photons are prepared originally in the same state （0） by the server...In this paper a scheme for quantum secure direct communication （QSDC） network is proposed with a sequence of polarized single photons. The single photons are prepared originally in the same state （0） by the servers on the network, which will reduce the difficulty for the legitimate users to check eavesdropping largely. The users code the information on the single photons with two unitary operations which do not change their measuring bases. Some decoy photons, which are produced by operating the sample photons with a Hadamard, are used for preventing a potentially dishonest server from eavesdropping the quantum lines freely. This scheme is an economical one as it is the easiest way for QSDC network communication securely.展开更多
文摘为了动态控制用于植物生长的人工光源，该文提出一种以光子数作为评价标准，使红蓝光比例连续可调的LED植物生长光源的配光方法。综合考虑红、蓝2种波段光源及其他光谱的作用，该文采用白光LED与红光LED 组合配比，以正向电流下 LED 的光谱密度数据作为计算基础，提出配光设计算法，实现红蓝成分有效光子数维持一定的要求下，红光与蓝光光子数比在指定区间（4：1～9：1之间）连续可调，从而满足植物不同生长状态对光质成分的需要。
基金the National Natural Science Foundation of China under Grant No.60378027.
文摘A new calibration method of detectors can be realized by using correlated photons generated in spontaneous parametric down-conversion （SPDC） effect of nonlinear crystal. An absolute calibration system of detector quantum efficiency is performed. And its principle and experimental setup are introduced. A continuouswave （CW） ultraviolet （351 nm）, diode-pumped, frequency-doubled, and solid-state laser is used to pump BBO crystal. The quantum efficiencies of the photomultiplier at 633, 702, and 789 nm are measured respectively. The coincidence peaks are observed using coincidence circuit. Some measurement factors including the filter bandwidth of trigger channel, the detector position alignment and polarization of the pump light are analyzed. The uncertainties of this calibration method are also analyzed, and the relative uncertainties of total calibration are less than 5.8%. The accuracy of this method could be improved in the future.
文摘QUANTIZED radiation fields exhibiting nonclassical properties have been of great theoretical andexperimental interest in the last two decades. It is shown that various nonclassical states suchas squeezed state and Schrodinger cat state can be generated out of coherent state in thenonlinear process of the interaction of atom and field although the radiation field in a
基金Project supported by the National Natural Science Foundation of China （Grant Nos 10604008 and 10435020） and the Beijing Education Committee （Grant No XK100270454）.
文摘In this paper a scheme for quantum secure direct communication （QSDC） network is proposed with a sequence of polarized single photons. The single photons are prepared originally in the same state （0） by the servers on the network, which will reduce the difficulty for the legitimate users to check eavesdropping largely. The users code the information on the single photons with two unitary operations which do not change their measuring bases. Some decoy photons, which are produced by operating the sample photons with a Hadamard, are used for preventing a potentially dishonest server from eavesdropping the quantum lines freely. This scheme is an economical one as it is the easiest way for QSDC network communication securely.
