Short-Length 10-W cw Neodymium-Doped M-Profile Fiber Laser

A comparative analysis of the mode field distributions of the pump radiation in a double-clad fiber laser and in an M-profile fiber laser shows the superiority of the latter design with respect to absorption efficiency. This efficiency is accurately modeled by the modal analysis, allowing the description of the lasing field within the same model. Based on this approach, the optimization of the recently invented M-profile fiber laser was carried out, leading to an output power of nearly 10 W at lambda = 1050 nm with a slope efficiency of 54% utilizing a fiber length of 190 cm.