Instability Due to Optical Nonlinearity in Passively Phased High-Power Fiber Amplifier Arrays

摘要

Using a simple physical model as argument, we predict the existence of a new instability that we note to be inherent to passively phased laser arrays having at least two elements, its origin being the nonlinearity of the medium and the collective properties of such arrays in the presence of coherent feedback. The prediction is confirmed by perturbation analysis and computer simulations of 2- and 3-element fiber amplifier arrays, and validated by the observation of dark soliton trains generated at power levels close to the predicted instability threshold.