This paper presents the development of a highly efficient CT-PCF (Core-Tune Photonic Crystal Fiber) with substantial birefringence, tailored for applications in high-bit-rate communication and sensing while minimizing...This paper presents the development of a highly efficient CT-PCF (Core-Tune Photonic Crystal Fiber) with substantial birefringence, tailored for applications in high-bit-rate communication and sensing while minimizing signal loss. The design incorporates a modified broadband dispersion compensating structure, optimized for operation across the E, S, C, and L communication bands within a wavelength range spanning 1360 nm to 1625 nm. Notably, the CT-PCF demonstrates a remarkable birefringence of 2.372 × 10<sup>-2</sup> at 1550 nm, surpassing traditional PCF structures. Single-mode performance is evaluated using the Higher Order Mode Extinction Ratio (HOMER) method, revealing a peak HOMER value of 10<sup>4</sup> at 1550 nm. Furthermore, at 1550 nm, the CT-PCF exhibits exceptional nonlinear characteristics, featuring a high nonlinearity of 50.74 W<sup>-1</sup>⋅Km<sup>-1</sup> for y polarization. In comparison to existing designs, the proposed CT-PCF exhibits superior performance metrics and optical characteristics. Additionally, the y polarization dispersion coefficient of the CT-PCF at 1550 nm is measured at -3534 ps/(nm⋅km). Overall, the CT-PCF represents a significant advancement, outperforming established systems in terms of performance metrics and optical properties.展开更多
The necessary derivation of negative mass in dispersion dynamics suggests cosmic applications. The method analyzes functional relationships between particle angular frequency, wave vector, rest mass and electromagneti...The necessary derivation of negative mass in dispersion dynamics suggests cosmic applications. The method analyzes functional relationships between particle angular frequency, wave vector, rest mass and electromagnetic or nuclear potential, f(ω, k, m0, V) = 0. A summary of consequential predictions of the dynamics leads to a calculation of ways in which negative mass might influence such phenomena as the rotational velocities that are observed in spiral galaxies. The velocities are found to be not Newtonian in the simple two body approximations for our solar system;but nearly constant with increasing orbital radii. It has moreover been suggested that the motion is due to halo structures of dark matter or dark energy. However, the motion is simply described by many-body gravitation that is transmitted along elastic spiral arms. In this context, we calculate possible effects of negative mass, but without observational confirmation.展开更多
A general method of simulation of processes in dusty based on special programs is presented here. It is pos-sible to prepare the modeling of the dusty in volcano like the dust sound waveguides. Dusty is in state of th...A general method of simulation of processes in dusty based on special programs is presented here. It is pos-sible to prepare the modeling of the dusty in volcano like the dust sound waveguides. Dusty is in state of the plasma .Waveguides are formed by the distribution of dusty particles with various masses m = m(x) in trans-verse coordinate. The dust sound waves propagate along the longitudinal z-direction. In the case of contact of dusty plasma with a semi-infinite dielectric, there exists the dust acoustic mode that possesses the negative group velocity (backward wave) in the specified interval of wave numbers. For analysis it is necessary to use the special numerical methods of calculation of the equations with boundary conditions. Simulation of ion sound wave propagation shows a new dispersion between frequency and wave vector. In some region of pa-rameters of dusty the negative dispersion of wave takes place. This means that the phase and group velocities of wave are opposite (negative dispersion). This phenomenon takes place, when the mass of dust particles has the maximum in the center of the waveguide. The negative dispersion caused the instability in dusty, which open the possibility to create a new phenomenon in dusty including the high temperature and the flame.展开更多
The enhanced high gain harmonic generation （EHGHG） scheme has been proposed and shown to be able to significantly enhance the performance of HGHG FEL. In this paper we investigate the EHGHG scheme with negative disp...The enhanced high gain harmonic generation （EHGHG） scheme has been proposed and shown to be able to significantly enhance the performance of HGHG FEL. In this paper we investigate the EHGHG scheme with negative dispersion. The bunching factor at the entrance of the radiator is analyzed, which indicates that the scheme with negative dispersion can further weaken the negative effect of the dispersive strength on the energy spread correction factor. The numerical results from GENESIS （3D-code） are presented, and are in good agreement with our analysis. Then we comparatively study the effects of the initial beam energy spread and the relative phase shift on the radiation power. The results show that the EHGHG scheme with negative dispersion has a larger tolerance on the initial beam energy spread and a nearly equal wide good region of the relative phase shift compared with the case of positive dispersion.展开更多
A planar magnetoinductive (MI) waveguide loaded rectangular microstrip patch antenna is presented and discussed. The MI waveguide consists of two planar metamaterial split squared ring resonators (SSRRs) placed in bet...A planar magnetoinductive (MI) waveguide loaded rectangular microstrip patch antenna is presented and discussed. The MI waveguide consists of two planar metamaterial split squared ring resonators (SSRRs) placed in between two microstrip lines. The backward wave propagation takes place through this structure. The rectangular microstrip patch antenna is magnetically coupled to the MI waveguide. The unloaded rectangular microstrip patch antenna resonates at 37.10 GHz. When loaded with planar MI waveguide, its resonant frequency is reduced to 9.38 GHz with the bandwidth and gain of 44% and 4.16 dBi respectively. In loaded condition, the dimension of antenna is 12.50 mm × 3.70 mm (0.390 λ × 0.115 λ). The appreciable bandwidth is achieved in such a small size antenna. The pass band frequency of MI waveguide is predicted by using the theoretical model of dispersion equation. The effective medium theory is used to verify the metamaterial characteristics of SSRR. The simulated results and theoretical calculations are also presented. The results show that the proposed method can be used to design compact and high bandwidth microstrip patch antennas.展开更多
It is measured by Wang et al. That a pulse advancement shift of 62(±1)ns gives from the shift an effective group velocity index of n g=-310(±5). A signal advancement shift was predicted by Einstein if the si...It is measured by Wang et al. That a pulse advancement shift of 62(±1)ns gives from the shift an effective group velocity index of n g=-310(±5). A signal advancement shift was predicted by Einstein if the signal propagation could exceed the vacuum speed of light. But Einstein was negative for this possibility, and hence negative the possibility about greater than the vacuum speed of light. Therefore, Einsteins prediction was testified negatively by the experiment of Wang et al. If we use a new structure of the spacetime, the Finsler spacetime d s 4, then the spacelike and the timelike can be equivalent on the new structure.展开更多
We theoretically investigate the intra-band transitions in Mobius molecules.Due to the weak magnetic response,the relative permittivity is significantly modified by the presence of the medium while the relative permea...We theoretically investigate the intra-band transitions in Mobius molecules.Due to the weak magnetic response,the relative permittivity is significantly modified by the presence of the medium while the relative permeability is not.We show that there is hyperbolic dispersion relation induced by the intra-band transitions because one of the eigen-values of permittivity possesses a different sign from the other two,while all three eigen-values of permeability are positive.We further demonstrate that the bandwidth of negative refraction is 0.165 eV for the H-polarized incident light,which is broader than the ones for inter-band transitions by 3 orders of magnitude.Moreover,the frequency domain has been shifted from ultra-violet to visible domain.Although there is negative refraction for the E-polarized incident light,the bandwidth is much narrower and depends on the incident angle.展开更多
文摘This paper presents the development of a highly efficient CT-PCF (Core-Tune Photonic Crystal Fiber) with substantial birefringence, tailored for applications in high-bit-rate communication and sensing while minimizing signal loss. The design incorporates a modified broadband dispersion compensating structure, optimized for operation across the E, S, C, and L communication bands within a wavelength range spanning 1360 nm to 1625 nm. Notably, the CT-PCF demonstrates a remarkable birefringence of 2.372 × 10<sup>-2</sup> at 1550 nm, surpassing traditional PCF structures. Single-mode performance is evaluated using the Higher Order Mode Extinction Ratio (HOMER) method, revealing a peak HOMER value of 10<sup>4</sup> at 1550 nm. Furthermore, at 1550 nm, the CT-PCF exhibits exceptional nonlinear characteristics, featuring a high nonlinearity of 50.74 W<sup>-1</sup>⋅Km<sup>-1</sup> for y polarization. In comparison to existing designs, the proposed CT-PCF exhibits superior performance metrics and optical characteristics. Additionally, the y polarization dispersion coefficient of the CT-PCF at 1550 nm is measured at -3534 ps/(nm⋅km). Overall, the CT-PCF represents a significant advancement, outperforming established systems in terms of performance metrics and optical properties.
文摘The necessary derivation of negative mass in dispersion dynamics suggests cosmic applications. The method analyzes functional relationships between particle angular frequency, wave vector, rest mass and electromagnetic or nuclear potential, f(ω, k, m0, V) = 0. A summary of consequential predictions of the dynamics leads to a calculation of ways in which negative mass might influence such phenomena as the rotational velocities that are observed in spiral galaxies. The velocities are found to be not Newtonian in the simple two body approximations for our solar system;but nearly constant with increasing orbital radii. It has moreover been suggested that the motion is due to halo structures of dark matter or dark energy. However, the motion is simply described by many-body gravitation that is transmitted along elastic spiral arms. In this context, we calculate possible effects of negative mass, but without observational confirmation.
文摘A general method of simulation of processes in dusty based on special programs is presented here. It is pos-sible to prepare the modeling of the dusty in volcano like the dust sound waveguides. Dusty is in state of the plasma .Waveguides are formed by the distribution of dusty particles with various masses m = m(x) in trans-verse coordinate. The dust sound waves propagate along the longitudinal z-direction. In the case of contact of dusty plasma with a semi-infinite dielectric, there exists the dust acoustic mode that possesses the negative group velocity (backward wave) in the specified interval of wave numbers. For analysis it is necessary to use the special numerical methods of calculation of the equations with boundary conditions. Simulation of ion sound wave propagation shows a new dispersion between frequency and wave vector. In some region of pa-rameters of dusty the negative dispersion of wave takes place. This means that the phase and group velocities of wave are opposite (negative dispersion). This phenomenon takes place, when the mass of dust particles has the maximum in the center of the waveguide. The negative dispersion caused the instability in dusty, which open the possibility to create a new phenomenon in dusty including the high temperature and the flame.
基金Supported by National Natural Science Foundation of China (10975137)
文摘The enhanced high gain harmonic generation （EHGHG） scheme has been proposed and shown to be able to significantly enhance the performance of HGHG FEL. In this paper we investigate the EHGHG scheme with negative dispersion. The bunching factor at the entrance of the radiator is analyzed, which indicates that the scheme with negative dispersion can further weaken the negative effect of the dispersive strength on the energy spread correction factor. The numerical results from GENESIS （3D-code） are presented, and are in good agreement with our analysis. Then we comparatively study the effects of the initial beam energy spread and the relative phase shift on the radiation power. The results show that the EHGHG scheme with negative dispersion has a larger tolerance on the initial beam energy spread and a nearly equal wide good region of the relative phase shift compared with the case of positive dispersion.
文摘A planar magnetoinductive (MI) waveguide loaded rectangular microstrip patch antenna is presented and discussed. The MI waveguide consists of two planar metamaterial split squared ring resonators (SSRRs) placed in between two microstrip lines. The backward wave propagation takes place through this structure. The rectangular microstrip patch antenna is magnetically coupled to the MI waveguide. The unloaded rectangular microstrip patch antenna resonates at 37.10 GHz. When loaded with planar MI waveguide, its resonant frequency is reduced to 9.38 GHz with the bandwidth and gain of 44% and 4.16 dBi respectively. In loaded condition, the dimension of antenna is 12.50 mm × 3.70 mm (0.390 λ × 0.115 λ). The appreciable bandwidth is achieved in such a small size antenna. The pass band frequency of MI waveguide is predicted by using the theoretical model of dispersion equation. The effective medium theory is used to verify the metamaterial characteristics of SSRR. The simulated results and theoretical calculations are also presented. The results show that the proposed method can be used to design compact and high bandwidth microstrip patch antennas.
文摘It is measured by Wang et al. That a pulse advancement shift of 62(±1)ns gives from the shift an effective group velocity index of n g=-310(±5). A signal advancement shift was predicted by Einstein if the signal propagation could exceed the vacuum speed of light. But Einstein was negative for this possibility, and hence negative the possibility about greater than the vacuum speed of light. Therefore, Einsteins prediction was testified negatively by the experiment of Wang et al. If we use a new structure of the spacetime, the Finsler spacetime d s 4, then the spacelike and the timelike can be equivalent on the new structure.
基金supported by the National Natural Science Foundation of China(Grant Nos.11505007,11674033,and 11474026).
文摘We theoretically investigate the intra-band transitions in Mobius molecules.Due to the weak magnetic response,the relative permittivity is significantly modified by the presence of the medium while the relative permeability is not.We show that there is hyperbolic dispersion relation induced by the intra-band transitions because one of the eigen-values of permittivity possesses a different sign from the other two,while all three eigen-values of permeability are positive.We further demonstrate that the bandwidth of negative refraction is 0.165 eV for the H-polarized incident light,which is broader than the ones for inter-band transitions by 3 orders of magnitude.Moreover,the frequency domain has been shifted from ultra-violet to visible domain.Although there is negative refraction for the E-polarized incident light,the bandwidth is much narrower and depends on the incident angle.
