Passive coherent combination of all-fiber multichannel pulsed laser based on optical feed-back ring cavity

Self-organized passive coherent beam combination of multichannel pulsed laser with all-fiber configuration is reported. The phase of multichannel Yb-doped pulsed fiber amplifiers is locked by optical feed-back ring cavity. The traditional disadvantage of energy dissipation to side lode for lower aperture filling is solved via all-fiber laser array with single-aperture configuration. Coherent beam combination of four pulsed fiber amplifiers is experimentally demonstrated. Variable pulsed laser can be obtained by adjusting a AOM,stable combination pulsed fiber laser with excellent temporal and spatial characteristic is achieved. The efficiency of coherent combination is up to 85.0%. This approach presented here provides a feasible technique for power scaling of high-power pulsed fiber laser and maintaining beam quality simultaneously.