Transverse mode propagation studies in a thulium-doped fiber laser

In this paper, we apply a transverse mode propagation model of thulium-doped fiber laser based on propagation equations. Based on this model the behaviors of transverse mode propagation are demonstrated and individual transverse mode power distributions of output are simulated numerically under various conditions including bending radius, fiber length, and pump power. Furthermore, the output power and beam quality characteristic for the thulium-doped fiber laser are investigated experimentally, and the experimental results agree well with the numerical results.