多波长级联拉曼光纤激光器的设计

Design of Multi-Wavelength Cascaded Raman Fiber Lasers

基于稳态条件下描述光纤中受激拉曼散射效应的光功率耦合方程组,提出一种新的多波长级联拉曼光纤激光器的设计算法。结合遗传算法和打靶法的优点,采取对每一代种群中少数优良个体进行几次打靶,使得种群中目标函数最优化值附近的个体加速收敛。以500 m掺磷光纤为增益介质、光纤布拉格光栅构成谐振腔的三波长(1427 nm,1455 nm,1480 nm)级联拉曼光纤激光器为例,采用该算法计算了其输出特性。结果表明,总输出功率与抽运功率近似成线性关系,斜率效率约51%;由于谐振腔中三个输出波长相互之间的受激拉曼散射作用产生的能量转移,使得输出的长波长斯托克斯光斜率效率大于短波长斯托克斯光斜率效率。

A novel design algorithm for the steady-state coupled power equations describing stimulated Raman scattering in Multi-wavelength cascaded Raman fiber lasers has been proposed, By taking the advantage of genetic algorithm and shooting method, a few elite individuals with the best fitness on each generation are chosen to implement several shootings to accelerate theirs converging. As an example, the output characteristics of an all-fiber three-wavelength （1427 rim, 1455 nm, and 1480 nm） Raman fiber laser with 500 meters P2O5-doped fiber as gain medium and fiber Bragg gratings as resonators has been analyzed with the algorithm. The results show that the total output power linearly depends on the pump power approximately with a slope efficiency of -51% ; the slop efficiency of longer wavelengths is larger than that of the shorter wavelengths due to the longer wavelengths gain additional power at the expense of the power of the shorter wavelengths.