Output performance of gain guided and index antiguided fiber lasers pumped by different methods

The output performance of Yb³⁺ doped gain guided and index antiguided (GG-IAG) fiber lasers pumped by different methods are compared by numerically solving rate equations (REs) with additional leakage losses. Three pump models, including forward pump, backward pump and bidirectional pump are established combined with REs model. Calculation results show that the output powers and slope efficiencies of GG-IAG fiber from high to low under the same condition are obtained by bidirectional pump, backward pump and forward pump in sequence. The upper energy level particle population density N₂(z) and thermal distribution along the fiber generated by bidirectional pump are more uniform than that by other two pump methods. It benefits the lasing of GG-IAG fiber most.