Adaptive shooting method for 4-point side-pumping high power Yb3+-doped double-clad fiber lasers

• Adaptive shooting method combines simple identification process and shooting method procedure.
• Adaptive shooting method can identify automatically eight cases with different pump scheme.
• Adaptive shooting method can update initial trial values by given function.
• Approximate expressions for pump and random functions of signal powers speed shooting method.
• Average iteration steps of adaptive shooting method are less than 8 for given tolerance.

An adaptive shooting method for solving 4-point side-pumping high power Yb3+-doped double-clad fiber lasers (YDCFLs) is developed. The adaptive shooting method combines the simple identification process and shooting method procedure. Simulation results show that the adaptive shooting method can identify automatically and easily eight different cases in the 4-point side-pumping YDCFLs with different pump schemes. The initial estimate values of pump powers as independent variables are given approximate expressions and the signal powers are set random functions to speed the adaptive shooting method. The adaptive shooting method can succeed rapidly to get the exact results after average less than eight iteration steps updating initial guess values.