The decoherence of high-dimensional orbital angular momentum(OAM)entanglement in the weak scintillation regime has been investigated.In this study,we simulate atmospheric turbulence by utilizing a multiple-phase scree...The decoherence of high-dimensional orbital angular momentum(OAM)entanglement in the weak scintillation regime has been investigated.In this study,we simulate atmospheric turbulence by utilizing a multiple-phase screen imprinted with anisotropic non-Kolmogorov turbulence.The entanglement negativity and fidelity are introduced to quantify the entanglement of a high-dimensional OAM state.The numerical evaluation results indicate that entanglement negativity and fidelity last longer for a high-dimensional OAM state when the azimuthal mode has a lower value.Additionally,the evolution of higher-dimensional OAM entanglement is significantly influenced by OAM beam parameters and turbulence parameters.Compared to isotropic atmospheric turbulence,anisotropic turbulence has a lesser influence on highdimensional OAM entanglement.展开更多
A dynamically tunable multiband plasmon-induced transparency(PIT) effect in a series of rectangle cavities coupled with a graphene nanoribbon waveguide system is investigated theoretically and numerically by tuning th...A dynamically tunable multiband plasmon-induced transparency(PIT) effect in a series of rectangle cavities coupled with a graphene nanoribbon waveguide system is investigated theoretically and numerically by tuning the Fermi level of the graphene rectangle cavity. A single-PIT effect is realized using two different methods: one is the direct destructive interference between bright and dark modes, and the other is the indirect coupling through a graphene nanoribbon waveguide. Moreover, dual-PIT effect is obtained by three rectangle cavities side-coupled with a graphene nanoribbon waveguide.Results show that the magnitude of the dual-PIT window can be controlled between 0.21 and 0.74, and the corresponding group index is controlled between 143.2 and 108.6. Furthermore, the triple-PIT effect is achieved by the combination of bright–dark mode coupling and the cavities side-coupled with waveguide mechanism. Thus, sharp PIT windows can be formed, a high transmission is maintained between 0.51 and 0.74, and the corresponding group index is controlled between161.4 and 115.8. Compared with previously proposed graphene-based PIT effects, the size of the introduced structure is less than 0.5 μm2. Particularly, the slow light effect is crucial in the current research. Therefore, a novel approach is introduced toward the realization of optical sensors, optical filters, and slow light and light storage devices with ultra-compact,multiband, and dynamic tunable.展开更多
An ultrafast and low-power slow light tuning mechanism based on plasmon-induced transparency(PIT)for two disk cavities aperture-coupled to a metal-dielectric-metal plasmonic waveguide system is investigated numericall...An ultrafast and low-power slow light tuning mechanism based on plasmon-induced transparency(PIT)for two disk cavities aperture-coupled to a metal-dielectric-metal plasmonic waveguide system is investigated numerically and analytically.The optical Kerr effect is enhanced by the local electromagnetic field of surface plasmon polaritons,slow light,and graphene-Ag composite material structures with a large effective Kerr nonlinear coefficient.Through the dynamic adjustment of the frequency of the disk nanocavity,the group velocity is controlled between c/53.2 and c/15.1 with the pump light intensity increased from 0.41 MW/cm^2 to 2.05 MW/cm^2.Alternatively,through the dynamic adjustment of the propagation phase of the plasmonic waveguide,the group velocity is controlled between c/2.8 and c/14.8 with the pump light intensity increased from 5.88 MW/cm^2 to 11.76 MW/cm^2.The phase shift multiplication of the PIT effect is observed.Calculation results indicate that the entire structure is ultracompact and has a footprint of less than 0.8μm^2.An ultrafast responsive time in the order of 1 ps is reached due to the ultrafast carrier relaxation dynamics of graphene.All findings are comprehensively analyzed through finite-difference time-domain simulations and with a coupling-mode equation system.The results can serve as a reference for the design and fabrication of nanoscale integration photonic devices with low power consumption and ultrafast nonlinear responses.展开更多
基金supported by the Project of the Hubei Provincial Department of Science and Technology(Grant Nos.2022CFB957,2022CFB475)the National Natural Science Foundation of China(Grant No.11847118)。
文摘The decoherence of high-dimensional orbital angular momentum(OAM)entanglement in the weak scintillation regime has been investigated.In this study,we simulate atmospheric turbulence by utilizing a multiple-phase screen imprinted with anisotropic non-Kolmogorov turbulence.The entanglement negativity and fidelity are introduced to quantify the entanglement of a high-dimensional OAM state.The numerical evaluation results indicate that entanglement negativity and fidelity last longer for a high-dimensional OAM state when the azimuthal mode has a lower value.Additionally,the evolution of higher-dimensional OAM entanglement is significantly influenced by OAM beam parameters and turbulence parameters.Compared to isotropic atmospheric turbulence,anisotropic turbulence has a lesser influence on highdimensional OAM entanglement.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11647122 and 61705064)the Natural Science Foundation of Hubei Province,China(Grant Nos.2018CFB672 and 2021CFB607)+1 种基金the Project of the Hubei Provincial Department of Education,China(Grant Nos.B2021215 and T201617)the Natural Science Foundation of Xiaogan City,China(Grant Nos.XGKJ2021010002 and XGKJ2021010003)。
文摘A dynamically tunable multiband plasmon-induced transparency(PIT) effect in a series of rectangle cavities coupled with a graphene nanoribbon waveguide system is investigated theoretically and numerically by tuning the Fermi level of the graphene rectangle cavity. A single-PIT effect is realized using two different methods: one is the direct destructive interference between bright and dark modes, and the other is the indirect coupling through a graphene nanoribbon waveguide. Moreover, dual-PIT effect is obtained by three rectangle cavities side-coupled with a graphene nanoribbon waveguide.Results show that the magnitude of the dual-PIT window can be controlled between 0.21 and 0.74, and the corresponding group index is controlled between 143.2 and 108.6. Furthermore, the triple-PIT effect is achieved by the combination of bright–dark mode coupling and the cavities side-coupled with waveguide mechanism. Thus, sharp PIT windows can be formed, a high transmission is maintained between 0.51 and 0.74, and the corresponding group index is controlled between161.4 and 115.8. Compared with previously proposed graphene-based PIT effects, the size of the introduced structure is less than 0.5 μm2. Particularly, the slow light effect is crucial in the current research. Therefore, a novel approach is introduced toward the realization of optical sensors, optical filters, and slow light and light storage devices with ultra-compact,multiband, and dynamic tunable.
基金the National Natural Science Foundation of China(Grant Nos.11647122 and 61705064)the Natural Science Foundation of Hubei Province,China(Grant Nos.2018CFB672 and 2018CFB773).
文摘An ultrafast and low-power slow light tuning mechanism based on plasmon-induced transparency(PIT)for two disk cavities aperture-coupled to a metal-dielectric-metal plasmonic waveguide system is investigated numerically and analytically.The optical Kerr effect is enhanced by the local electromagnetic field of surface plasmon polaritons,slow light,and graphene-Ag composite material structures with a large effective Kerr nonlinear coefficient.Through the dynamic adjustment of the frequency of the disk nanocavity,the group velocity is controlled between c/53.2 and c/15.1 with the pump light intensity increased from 0.41 MW/cm^2 to 2.05 MW/cm^2.Alternatively,through the dynamic adjustment of the propagation phase of the plasmonic waveguide,the group velocity is controlled between c/2.8 and c/14.8 with the pump light intensity increased from 5.88 MW/cm^2 to 11.76 MW/cm^2.The phase shift multiplication of the PIT effect is observed.Calculation results indicate that the entire structure is ultracompact and has a footprint of less than 0.8μm^2.An ultrafast responsive time in the order of 1 ps is reached due to the ultrafast carrier relaxation dynamics of graphene.All findings are comprehensively analyzed through finite-difference time-domain simulations and with a coupling-mode equation system.The results can serve as a reference for the design and fabrication of nanoscale integration photonic devices with low power consumption and ultrafast nonlinear responses.
