Experimental results of spectral beam combining using large-mode-area double-cladding fiber lasers

Based on the design scheme of spectral beam combining using transmitting volume Bragg grating, the experimental results for spectral beam combining of two fiber lasers are reported. The gain mediums used in this experiment were two large mode area erbium-ytterbium co-doped double-cladding fibers, pumped by semiconductor lasers. The output powers of the two fiber lasers were 0.39 W and 0.53 W respectively. With grating diffraction efficiency lower than 60%, the maximal output power of 0.64 W with absolute combining efficiency of about 69.6% was achieved. The influencing factors of the combining efficiency in the experiment are analyzed.