在含涂覆层的标准通信光纤中,用红外飞秒激光直接写入长周期光纤光栅(long period fiber gratings,LPFGs),并通过理论和实验分析,研究含涂覆层LPFGs的轴向应变特性.分析结果表明,与去除涂覆层的LPFGs相比,涂覆层的存在不仅增强了LPFGs的机械强度,同时有效地抑制了LPFGs由外加应变引起的谐振波长偏移.基于以上优点,含涂覆层的LPFGs若作为带阻滤波器或增益平坦器,将有良好的机械可靠性和波长应变稳定性.
The propagation of spatial solitons is systematically investigated in nonlocal nonlinear media with an imprinted transverse periodic modulation of the refractive index. Based on the variational principle and the infinitesimal approximation of Maclaurin series expansion, we obtain an analytical solution of such nonlocal spatial solitons and an interesting result that the critical power for such solitons propagation is smaller than that in uniform nonlocal self-focusing media. It is found that there exist thresholds in modulation period and lattice depth for such solitons. A stable spatial soliton propagation is maintained with proper adjustment of the modulation period and the lattice depth.
This paper studies the propagation of dipole solitons in highly nonlocal medium by using the variational method. It finds that the dipole solitons will be stable when the input power obeys a restrict value. When the incident power does not satisfy the stable conditions, the nonlocal accessible dipole solitons will undergo linear harmonic oscillation. It shows such evolution behaviours in detail.
This paper studies analytically and numerically the dynamics of two-dimensional elliptical Gaussian solitons in a ＂double-self-focusing＂ synthetic nonlocal media featuring elliptical and circular Gaussian response with different degrees of nonlocality. Based on the variational approach, it obtains the approximately analytical solution of such Gaussian elliptical solitons. It also computes the stability of the solitons by numerical simulations.
