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 symmetric