The analytic formulae of probability distribution of spiral plane modes for the Whittaker-Gaussian （WG） beams with orbital angular momentum （OAM） in strong turbulence regime are modeled based on the modified Rytov...The analytic formulae of probability distribution of spiral plane modes for the Whittaker-Gaussian （WG） beams with orbital angular momentum （OAM） in strong turbulence regime are modeled based on the modified Rytov approximation. Numerical results show that the erosstalk range of OAM modes in the vicinity of signal mode increases with the increasing refractive-index construction parameter. However, effects of change of the width of the Gaussian envelope and the parameter Wo of WG beams on normalization energy weight of signal mode can be ignored. We find theoretically that signal spiral plane mode of WG beams at each OAM level approximatively has the same normalization energy weight, implying that the channels with WG （pseudo non-diffraction） beam have higher channel capacity than the channels with the Laguerre-Gaussian beam.展开更多
A direct current（DC） source excited plasma jet consisting of a hollow needle anode and a plate cathode has been developed to form a diffuse discharge plume in ambient air with flowing argon as the working gas.Using ...A direct current（DC） source excited plasma jet consisting of a hollow needle anode and a plate cathode has been developed to form a diffuse discharge plume in ambient air with flowing argon as the working gas.Using optical and electrical methods,the discharge characteristics are investigated for the diffuse plasma plume.Results indicate that the discharge has a pulse characteristic,under the excitation of a DC voltage.The discharge pulse corresponds to the propagation process of a plasma bullet travelling from the anode to the cathode.It is found that,with an increment of the gas flow rate,both the discharge plume length and the current peak value of the pulsed discharge decrease in the laminar flow mode,reach their minima at about1.5 L/min,and then slightly increase in the turbulent mode.However,the frequency of the pulsed discharge increases in the laminar mode with increasing the argon flow rate until the argon flow rate equals to about 1.5 L/min,and then slightly decreases in the turbulent mode.展开更多
基金Supported by the Fundamental Research Funds for the Central Universities under Grant No JUSRP51517the Graduate Student Research Innovation Project of Jiangsu-Province General University under Grant No KYLX15_1187
文摘The analytic formulae of probability distribution of spiral plane modes for the Whittaker-Gaussian （WG） beams with orbital angular momentum （OAM） in strong turbulence regime are modeled based on the modified Rytov approximation. Numerical results show that the erosstalk range of OAM modes in the vicinity of signal mode increases with the increasing refractive-index construction parameter. However, effects of change of the width of the Gaussian envelope and the parameter Wo of WG beams on normalization energy weight of signal mode can be ignored. We find theoretically that signal spiral plane mode of WG beams at each OAM level approximatively has the same normalization energy weight, implying that the channels with WG （pseudo non-diffraction） beam have higher channel capacity than the channels with the Laguerre-Gaussian beam.
基金supported by National Natural Science Foundation of China(Nos.10805013,11375051)Funds for Distinguished Young Scientists of Hebei Province,China(No.A2012201045)+1 种基金Department of Education for Outstanding Youth Project of China(No.Y2011120)Youth Project of Hebei University of China(No.2011Q14)
文摘A direct current（DC） source excited plasma jet consisting of a hollow needle anode and a plate cathode has been developed to form a diffuse discharge plume in ambient air with flowing argon as the working gas.Using optical and electrical methods,the discharge characteristics are investigated for the diffuse plasma plume.Results indicate that the discharge has a pulse characteristic,under the excitation of a DC voltage.The discharge pulse corresponds to the propagation process of a plasma bullet travelling from the anode to the cathode.It is found that,with an increment of the gas flow rate,both the discharge plume length and the current peak value of the pulsed discharge decrease in the laminar flow mode,reach their minima at about1.5 L/min,and then slightly increase in the turbulent mode.However,the frequency of the pulsed discharge increases in the laminar mode with increasing the argon flow rate until the argon flow rate equals to about 1.5 L/min,and then slightly decreases in the turbulent mode.
