Effects of phase errors on phase locking of all-fiber laser arrays

The effects of phase errors on phase locking of the all-fiber laser array are discussed. By analyzing the 5-fiber laser array, it is found that the phase properties of the array depend on the order of the magnitude of the inevitable random phase errors in the fiber lasers. The dynamics of maximum phase deviations are also traced to seek the condition of phase locking for the 5-fiber laser arrays. The results indicate that the random phase errors in the fiber lasers are required to be as small as 10−7 to ensure coherent beam combining of the array with a high efficiency. The 10- and 19-fiber laser arrays are also investigated, and the results are identical to those of the 5-fiber laser array. With the increase in the number of fiber lasers, “quasi-in-phase” state can always be realized until the random phase errors are controlled in the range (0,10−7).

► We analyze the effects of random phase errors on the phase locking of the all-fiber laser arrays.
► The phase properties depend on the size of the inevitable random phase errors.
► A high efficient coherent beam combining requires the random phase errors less than 10−7.
► Increasing the array size decreases the tolerance of the phase errors.