We study bright solitons in the fractional coupler with a spatially periodical modulated nonlinearity. The results show that the linear coupling constant $\kappa$, Lévy index $\alpha$, chemical potential $\mu$ and nonlinear intensity $g$ have a significant influence on the amplitude, width and stability of fundamental solitons, dipole solitons and tripole solitons. We investigate the stability of bright solitons by linear stability analysis and the real-time evolution method. It is found that the bright solitons tend to be stable with the increase of linear coupling constant, Lévy index, chemical potential, and nonlinear intensity in the corresponding parameter interval. The results also show that the distance between adjacent peaks is four times of the nonlinear lattice period for dipole solitons and six times for tripole solitons. We also find that the number of soliton peaks is smaller, and the stable region is wider in the fractional coupler with the spatially periodical modulated nonlinear lattice.

我们研究了具有空间周期性调制非线性的分数耦合器中的亮孤子。结果表明，线性耦合常数$\kappa$, 莱维指数$\alpha$, 化学势$\mu$和非线性强度$G$对基本孤子、偶极子孤子和三极子孤子的幅度、宽度和稳定性有显着影响。我们通过线性稳定性分析和实时演化方法研究了亮孤子的稳定性。发现亮孤子在相应参数区间内随着线性耦合常数、Lévy指数、化学势和非线性强度的增加而趋于稳定。结果还表明，相邻峰之间的距离对于偶极子孤子是非线性晶格周期的四倍，对于三极子孤子是六倍。我们还发现，具有空间周期调制非线性晶格的分数耦合器中孤子峰的数量较少，稳定区域较宽。