Despite the wide range of applications and versatility, actively Q-switched fiber lasers (AQS-FLs) suffer from the multi-peak phenomenon or stepwise pulse generation under certain conditions. As such, the advantage of the stepwise tendency in AQS-FL to modify the pulse shape and create a temporal profile that minimizes the power of stimulated Brillouin scattering (SBS) and stimulated Raman scattering (SRS) Stokes components is taken. Accordingly a multi-objective genetic algorithm (GA) and a Monte-Carlo method is developed to solve the improved model for SBS. Additionally, the suppression of SRS is predicted and examined successfully. The proposed method is deployed for the simulation of the 5 and 10 kW peak and 10 ns wide pulses on a 4 m long, single-mode, ytterbium-doped double clad fiber under the narrow linewidth of 0.05 nm with promising suppression of SBS and SRS effects. To the best of the authors' knowledge this is the first time that such a pulse-shaping strategy is demonstrated for the SBS or SRS suppression. Furthermore reaching a 10 kW peak on single mode fibers was previously only possible via custom made fibers. Our novel method offers the possibility of optimizing and improving the utilization of different fiber types in AQS-FL systems.

中文翻译：

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通过时间脉冲整形抑制主动调Q光纤激光器中的受激布里渊和拉曼散射

尽管具有广泛的应用和多功能性，但主动调 Q 光纤激光器 (AQS-FL) 在某些条件下仍会出现多峰现象或逐步产生脉冲。因此，采用了 AQS-FL 中逐步趋势的优势，以修改脉冲形状并创建时间分布图，从而最大限度地减少受激布里渊散射 (SBS) 和受激拉曼散射 (SRS) 斯托克斯分量的功率。因此，开发了多目标遗传算法（GA）和蒙特卡洛方法来求解改进的 SBS 模型。此外，SRS 的抑制被成功预测和检查。所提出的方法用于在 4 m 长、单模、掺镱双包层光纤上模拟 5 kW 和 10 kW 峰值和 10 ns 宽脉冲，线宽为 0. 05 nm 有希望抑制 SBS 和 SRS 效应。据作者所知，这是第一次为 SBS 或 SRS 抑制演示这种脉冲整形策略。此外，在单模光纤上达到 10 kW 峰值以前只能通过定制光纤来实现。我们的新方法提供了优化和提高 AQS-FL 系统中不同光纤类型利用率的可能性。