Coherent beam combination of a hexagonal distributed high power fiber amplifier array

摘要

We demonstrate the coherent beam combination of a hexagonal distributed high power fiber amplifier array. Six polarization-maintained fiber amplifiers are tiled into a hexagonal array by use of a novel beam combiner. The phase control signal for fiber amplifiers is generated by running a stochastic parallel gradient descent algorithm on a digital signal processor. The coherent beam combination with a total output power of 73.5 W is demonstrated. The contrast of the coherent combined beam profile is as high as 81percent when the system is closed-loop controlled.