An Efficient Algorithm Based on Propagation Equations of Tm3+-Doped Double-Clad Fiber Laser

An efficient, simple and fast algorithm with the least calculation based on the propagation equations of Tm-doped double-clad fiber laser is proposed. Based on this algorithm, the initial guessing value is directly corrected based on the relation of the two-end boundary values of laser power when the guessed value does not satisfy the boundary conditions, and it is not necessary to know the initial or terminal laser power. The evolutions of the propagation pump and laser powers along the fiber are analyzed by the efficient algorithm. It is proved that the initial guessed laser power can be fast convergent to the truth value regardless of the magnitude of the initial guessed laser power, and this algorithm can be effective even if the pump power is up to kilowatt level. Finally, compared with the improved shooting algorithm based on the Newton-Raphson method, the iteration progress of this algorithm is easier when the initial guessed value do not satisfy the boundary conditions, and the running time is at least 2 times as fast as that of the improved shooting algorithm, so this algorithm can be more quickly and simpler convergent to the truth value. So, this algorithm can be used in the Tm3+-doped double-clad fiber laser efficiently.