Thermal stress in Yb-doped double-clad fiber lasers

Aim at the model of Yb-doped double-clad fiber lasers (DCFL),the parameter impacting the maximum thermal stress of clad surface such as radius of core,pump fashion,pump absorption coefficients are studied.Results indicate that serious problems such as fracture are caused around core and clad sur- face of the laser.Increasing the core radius and fiber length can reduce the maximun thermal stress of clad surface.The two end symmetrical pump fashion is more superiority than other pump fashion.So an approach with nonuniform pump absorption coefficients is proposed to reach the reduction of the maximum thermal stress of clad surface and high output power.