为了提高受激布里渊散射慢光的延时和抑制脉冲展宽，通过四阶Runge-Kutta法和特征线法对基于光纤的受激布里渊散射耦合方程组进行数值求解，计算了斯托克斯脉冲边沿陡峭程度、功率、宽度对延迟时间以及脉冲展宽因子的影响，提出了在低频范围内适当提高斯托克斯脉冲的边沿陡峭程度, 可以优化延时和脉冲展宽因子的方法。该方法可以获得与高斯脉冲近似相等的延时和很小的脉冲展宽因子。基于波形能量差异的理论分析也证实了提高边沿陡峭程度对抑制脉冲展宽有明显的影响。

In order to increase time delay and decrease pulse broadening via stimulated-Brillouin scattering slow light, the coupled amplitude equations of stimulated Brillouin scattering in optical fibers are solved with fourth-order Runge-Kutta formula and characteristic-line mothod, the influence of the edge sharpness, magnitude and duration of injected Stokes pulse on time delay and pulse broadening factor are investigated. A method of optimizing time delay and pulse broadening factor is represented, namely, increasing the sharpness of Stokes pulse appropriately. Comparing with using Gaussian pulse as injected Stokes pulse, the similar time delay and less pulse broadening factor are obtained by this method. Theoretical analysis based on different power of injected Stokes pulse proves that improving the sharpness of injected Stokes pulse contributes a lot to reduce pulse broadening factor.