双包层光纤激光器的受激拉曼散射与热应力

 建立了高功率掺镱双包层光纤激光器的速率方程模型与热应力模型，对影响受激拉曼散射效应和热应力效应的关键参数（如纤芯半径、光纤长度、泵浦波长、泵浦方式）进行了数值模拟。结果表明:对于较小的纤芯半径，光纤内的斯托克斯光功率较大且增长迅速，因此增加纤芯半径能有效减弱受激拉曼散射效应；减小光纤长度能提高受激拉曼散射的阈值，而纤芯的热应力也增大，因此在不出现热应力引起光纤断裂的情况下，可以减小光纤长度以提高输出功率；采用976 nm波段泵浦源能提高输出功率，降低热应力的影响；两端均匀泵浦方式可以有效降低纤芯热应力，同时维持高功率输出。

Stimulated Raman scattering and thermal stress in double clad fiber laser

Establishing the rate equation model and thermal stress model of Yb-doped double-clad fiber lasers(DCFL),the key parameters impacting the stimulated Raman scattering(SRS) and thermal stress (such as the radius of core,the fiber length,the pump wavelength,and the pump fashion) are numerically simulated.The results indicate that the Stokes power is larger and grow rapidly for the smaller core radius,increasing the core radius will weaken the effect of SRS.Reducing the fiber length can increase the threshold of SRS,but the thermal stress of core will increase too;hence without fiber fracture induced by thermal stress,reducing fiber length can improve the output power.Adopting the pump source of 976 nm can improve the output power and reduce the thermal stress.The two end symmetrical pump fashion can reduce the thermal stress of core effectively and keep high output power.