Coherent combination of mutual injection phase-locked fiber lasers with a corner cube reflector

We present a new method of the mutual injection phase-locked coherent combination of fiber lasers based on corner cube reflector (CCR). The theoretic calculation of phase difference and far-field intensity distribution of coherent beams obtained by the CCR has been carried out on this work. The relation between the far-field optical intensity distribution and the CCR rotation angles is analyzed in the case of mutual injection. The coherent combination experiments of mutual injection phase-locked with two and four fiber lasers are performed. The experimental results reveal that the far-field intensity distribution in the two free running fiber lasers is good agreement with the theoretical calculation. In the two internal mutual injection structures, the coherent combination output power goes up as high as 54 W, and power combined efficiency of more than 90% and fringe contrast about 90% are obtained. The far-field intensity distribution is the same as the typical coherent combination pattern of two-dimensional fiber laser arrays, the experimental results also show that the coherent combination output with more laser beams and higher power with a good beam quality could be realized by the current scheme.