In this study,we reconstruct theγ-photon energy spectrum,which is in good agreement with the experimental data of ^(86)Kr+^(12)C at E/A=44 Me V within the framework of the modified EQMD model.The directed and ellipti...In this study,we reconstruct theγ-photon energy spectrum,which is in good agreement with the experimental data of ^(86)Kr+^(12)C at E/A=44 Me V within the framework of the modified EQMD model.The directed and elliptic flows of free protons and direct photons were investigated by considering theα-clustering structure of ^(12)C.Compared with free protons,direct photon flows provide clearer information about the early stage of a nuclear reaction.The difference in the collective flows between different configurations of ^(12)C is observed in this study.This indicates that the collective flows of direct photons are sensitive to the initial configuration.Therefore,theγbremsstrahlung process might be taken as an alternative probe to investigate theα-clustering structure in a light nucleus from heavy-ion collisions within the Fermienergy region.展开更多
Using the statistical model of parton and applying the rescaling model tochoose nuclear parameters by fitting the experimental data in low-X and medium-X re-gion,the influence of EMC(European Muon Collaboration)effect...Using the statistical model of parton and applying the rescaling model tochoose nuclear parameters by fitting the experimental data in low-X and medium-X re-gion,the influence of EMC(European Muon Collaboration)effect on large-P_T directphoton production is studied.The result shows that the influence of EMC effect issmall.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
In this paper a compact polarization beam splitter based on a deformed photonic crystal directional coupler is designed and simulated. The transverse-electric （TE） guided mode and transverse-magnetic （TM） guided m...In this paper a compact polarization beam splitter based on a deformed photonic crystal directional coupler is designed and simulated. The transverse-electric （TE） guided mode and transverse-magnetic （TM） guided mode are split due to different guiding mechanisms. The effect of the shape deformation of the air holes on the coupler is studied. It discovered that the coupling strength of the coupled waveguldes is strongly enhanced by introducing elliptical airholes, which reduce the device length to less than 18.Sttm. A finite-difference tlme-domain simulation is performed to evaluate the performance of the device, and the extinction ratios for both TE and TM polarized light are higher than 20 dB.展开更多
We work on photon production through annihilation and Compton, and annihilation with scattering (AWS) processes through a quark-gluon plasma (QGP) in high energy nuclear collision incorporating the parametrization fac...We work on photon production through annihilation and Compton, and annihilation with scattering (AWS) processes through a quark-gluon plasma (QGP) in high energy nuclear collision incorporating the parametrization factors in strong coupling value and thermal dependent quark mass obtained through a coupling value. We find that photon yield increases with the increasing of the temperature and dominated by early times. We also compare the influence of coupling value on the spectrum of thermal photons. The production rate of photons is observed in the range of low and intermediate transverse momentum. The results are compared with other work.展开更多
Transmission of electromagnetic waves through a Si-based one dimensional photonic crystal has been investigated. The proposed structure works as an omni-directional reflector for a certain range of wavelength for an a...Transmission of electromagnetic waves through a Si-based one dimensional photonic crystal has been investigated. The proposed structure works as an omni-directional reflector for a certain range of wavelength for an angle of incidence up to 55?. The structure works as a narrow band TM-polarization filter for an angle of incidence more than 55?, i.e. a filter which completely blocks TE-polarized waves but allows certain wavelengths of TM-polarized waves. But at an angle of incidence of 89?, the structure works as a multiple narrow band TM-polarization filter even though no defect layer is introduced inside the structure. It is also found that this multiple narrow pass-bands of TM-polarized waves can be tuned to a desired range of wavelength by changing the temperature of the structure.展开更多
The nonlinear absorption properties of direct (GaN) and indirect (CdI2) band gap crystals have been studied by using an open aperture Z-scan technique under fundamental (1064 nm) and frequency doubled (532 nm) wavelen...The nonlinear absorption properties of direct (GaN) and indirect (CdI2) band gap crystals have been studied by using an open aperture Z-scan technique under fundamental (1064 nm) and frequency doubled (532 nm) wavelength respectively with 10 ns or 60 ps pulse durations. Direct band gap crystal exhibits two and three photon absorption at all input irradiances. On the other hand, at low input irradiance the indirect band gap crystal exhibits saturable absorption (SA). At higher input irradiances two and three photon absorption becomes dominant. A monotonic increase of the nonlinear absorption coefficients with increasing laser pulse duration from 60 ps to 10 ns is observed for GaN and CdI2 crystals.展开更多
基金supported by the Guangdong Major Project of Basic and Applied Basic Research(No.2020B0301030008)the National Natural Science Foundation of China(Nos.11890710,11890714,and 11961141003)the Strategic Priority Research Program of the CAS(No.XDB34000000)。
文摘In this study,we reconstruct theγ-photon energy spectrum,which is in good agreement with the experimental data of ^(86)Kr+^(12)C at E/A=44 Me V within the framework of the modified EQMD model.The directed and elliptic flows of free protons and direct photons were investigated by considering theα-clustering structure of ^(12)C.Compared with free protons,direct photon flows provide clearer information about the early stage of a nuclear reaction.The difference in the collective flows between different configurations of ^(12)C is observed in this study.This indicates that the collective flows of direct photons are sensitive to the initial configuration.Therefore,theγbremsstrahlung process might be taken as an alternative probe to investigate theα-clustering structure in a light nucleus from heavy-ion collisions within the Fermienergy region.
基金The project supported in part by the Provincial Science Foundation of Fujian,China.
文摘Using the statistical model of parton and applying the rescaling model tochoose nuclear parameters by fitting the experimental data in low-X and medium-X re-gion,the influence of EMC(European Muon Collaboration)effect on large-P_T directphoton production is studied.The result shows that the influence of EMC effect issmall.
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.
基金supported by National Key Basic Research Special Fund of China (Grand No 2006CB921701-705)
文摘In this paper a compact polarization beam splitter based on a deformed photonic crystal directional coupler is designed and simulated. The transverse-electric （TE） guided mode and transverse-magnetic （TM） guided mode are split due to different guiding mechanisms. The effect of the shape deformation of the air holes on the coupler is studied. It discovered that the coupling strength of the coupled waveguldes is strongly enhanced by introducing elliptical airholes, which reduce the device length to less than 18.Sttm. A finite-difference tlme-domain simulation is performed to evaluate the performance of the device, and the extinction ratios for both TE and TM polarized light are higher than 20 dB.
文摘We work on photon production through annihilation and Compton, and annihilation with scattering (AWS) processes through a quark-gluon plasma (QGP) in high energy nuclear collision incorporating the parametrization factors in strong coupling value and thermal dependent quark mass obtained through a coupling value. We find that photon yield increases with the increasing of the temperature and dominated by early times. We also compare the influence of coupling value on the spectrum of thermal photons. The production rate of photons is observed in the range of low and intermediate transverse momentum. The results are compared with other work.
文摘Transmission of electromagnetic waves through a Si-based one dimensional photonic crystal has been investigated. The proposed structure works as an omni-directional reflector for a certain range of wavelength for an angle of incidence up to 55?. The structure works as a narrow band TM-polarization filter for an angle of incidence more than 55?, i.e. a filter which completely blocks TE-polarized waves but allows certain wavelengths of TM-polarized waves. But at an angle of incidence of 89?, the structure works as a multiple narrow band TM-polarization filter even though no defect layer is introduced inside the structure. It is also found that this multiple narrow pass-bands of TM-polarized waves can be tuned to a desired range of wavelength by changing the temperature of the structure.
文摘The nonlinear absorption properties of direct (GaN) and indirect (CdI2) band gap crystals have been studied by using an open aperture Z-scan technique under fundamental (1064 nm) and frequency doubled (532 nm) wavelength respectively with 10 ns or 60 ps pulse durations. Direct band gap crystal exhibits two and three photon absorption at all input irradiances. On the other hand, at low input irradiance the indirect band gap crystal exhibits saturable absorption (SA). At higher input irradiances two and three photon absorption becomes dominant. A monotonic increase of the nonlinear absorption coefficients with increasing laser pulse duration from 60 ps to 10 ns is observed for GaN and CdI2 crystals.
