The Experts below are selected from a list of 22908 Experts worldwide ranked by ideXlab platform

Javid Atai - One of the best experts on this subject based on the ideXlab platform.

  • moving bragg grating solitons in a semilinear dual core system with dispersive reflectivity
    Scientific Reports, 2017
    Co-Authors: S Saddam A M Chowdhury, Javid Atai
    Abstract:

    The existence, stability and collision dynamics of moving Bragg grating solitons in a semilinear dual-core system where one core has the Kerr nonlinearity and is equipped with a Bragg grating with dispersive reflectivity, and the other core is linear are investigated. It is found that moving soliton solutions exist as a continuous family of solutions in the upper and lower gaps of the system’s linear spectrum. The stability of the moving solitons are investigated by means of systematic numerical stability analysis, and the effect and interplay of various parameters on soliton stability are analyzed. We have also systematically investigated the characteristics of collisions of counter-propagating solitons. In-Phase collisions can lead to a variety of outcomes such as passage of solitons through each other with increased, reduced or unchanged velocities, asymmetric separation of solitons, merger of solitons into a quiescent one, formation of three solitons (one quiescent and two moving ones) and destruction of both solitons. The outcome regions of in-Phase collisions are identified in the plane of dispersive reflectivity versus frequency. The effects of coupling coefficient, relative group velocity in the linear core, soliton velocity and dispersive reflectivity and the Initial Phase Difference on the outcomes of collisions are studied.

Pierre A Deymier - One of the best experts on this subject based on the ideXlab platform.

  • experimental evidence of zero angle refraction and acoustic wave Phase control in a two dimensional solid solid phononic crystal
    Physical Review B, 2012
    Co-Authors: Jero Me Vasseur, N Swinteck, Antoine Tinel, Bruno Morvan, A C Hladkyhennion, Pierre A Deymier
    Abstract:

    The square symmetry of the equifrequency contour of longitudinal waves in a solid/solid two-dimensional phononic crystal (PC) is shown through numerical calculations and experiments to lead to peculiar propagation phenomena. A slab of steel/epoxy PC immersed in water refracts incident longitudinal waves by an angle of zero degrees. The waves propagate along the shortest path between the slab faces. This characteristic enables the superposition within the same volume of the PC of waves with different incidence angles. Two incident waves with symmetrical incident angles can interfere constructively or destructively inside the PC depending on their Initial Phase Difference. This Phase Difference is shown to enable control of wave propagation through the PC.

S Saddam A M Chowdhury - One of the best experts on this subject based on the ideXlab platform.

  • moving bragg grating solitons in a semilinear dual core system with dispersive reflectivity
    Scientific Reports, 2017
    Co-Authors: S Saddam A M Chowdhury, Javid Atai
    Abstract:

    The existence, stability and collision dynamics of moving Bragg grating solitons in a semilinear dual-core system where one core has the Kerr nonlinearity and is equipped with a Bragg grating with dispersive reflectivity, and the other core is linear are investigated. It is found that moving soliton solutions exist as a continuous family of solutions in the upper and lower gaps of the system’s linear spectrum. The stability of the moving solitons are investigated by means of systematic numerical stability analysis, and the effect and interplay of various parameters on soliton stability are analyzed. We have also systematically investigated the characteristics of collisions of counter-propagating solitons. In-Phase collisions can lead to a variety of outcomes such as passage of solitons through each other with increased, reduced or unchanged velocities, asymmetric separation of solitons, merger of solitons into a quiescent one, formation of three solitons (one quiescent and two moving ones) and destruction of both solitons. The outcome regions of in-Phase collisions are identified in the plane of dispersive reflectivity versus frequency. The effects of coupling coefficient, relative group velocity in the linear core, soliton velocity and dispersive reflectivity and the Initial Phase Difference on the outcomes of collisions are studied.

Yan Yan - One of the best experts on this subject based on the ideXlab platform.

  • numerical study of free surface flow in a 3 dimensional flng tank under coupled rotational heave excitations
    Journal of Marine Science and Technology, 2018
    Co-Authors: Yan Yan, J M Pfotenhauer, Franklin Miller
    Abstract:

    In this paper, free surface flow in a full-sized 3D FLNG tank is numerically studied under coupled rotational–heave excitations. The numerical model uses the standard k–e turbulence model and the volume of fluid method to describe fluid flow and track free surface. The emphasis of this study is making use of a full-sized tank with coupled excitations. A mesh independence study and comparison with other experiment and numerical simulation are implemented to verify the computational model. By parametrically investigating the influence of the Initial Phase Difference, heave frequency and filling ratio, it is found that an Initial Phase Difference of 0.5π and 1π can result in a higher local pressure near the tank corner and 0.5π will lead to a bigger amplitude of surface sloshing. A heave frequency of 2 times the natural frequency makes the surface sloshing flow most violent, but a heave frequency larger than that will turn the sloshing pattern into an up-and-down oscillation. A low filling ratio is more sensitive to both single rotational excitation and coupled excitations. However, a high filling ratio is relatively stable under rotation alone, but becomes much more violent from an induced heave excitation.

Jie Zhang - One of the best experts on this subject based on the ideXlab platform.

  • controllable terahertz radiation from a linear dipole array formed by a two color laser filament in air
    Physical Review Letters, 2016
    Co-Authors: Zhelin Zhang, Yanping Chen, Min Chen, Zhen Zhang, Zhengming Sheng, Jie Zhang
    Abstract:

    We demonstrate effective control on the carrier-envelope Phase and angular distribution as well as the peak intensity of a nearly single-cycle terahertz pulse emitted from a laser filament formed by two-color, the fundamental and the corresponding second harmonics, femtosecond laser pulses propagating in air. Experimentally, such control has been performed by varying the filament length and the Initial Phase Difference between the two-color laser components. A linear-dipole-array model, including the descriptions of both the generation (via laser field ionization) and propagation of the emitted terahertz pulse, is proposed to present a quantitative interpretation of the observations. Our results contribute to the understanding of terahertz generation in a femtosecond laser filament and suggest a practical way to control the electric field of a terahertz pulse for potential applications.