Coherent combining of evanescent coupled fiber laser array

Evanescent coupled fiber laser array was described and studied. Array modes were derived by applying the static eigenmode/supermode theory. The stability of output power, the array scalability and the array mode were analyzed by numerically studying the dynamical characteristics of the laser array system. The array modes based on the above two methods were compared and analyzed. The results show that the output power level and the power stability are directly affected by the phase locking property and the relative phase errors respectively. With the increase of laser elements, the total output power of the array increases nonlinearly. By tracking the phases of array elements and examining the laser array property in both near and far fields, the evidence that at least 37 fibers can be coherently combined, is given. With the increase of fiber elements, the power differences between central element and its neighbors become smaller gradually.