Selection of optical modes in multichannel fibre lasers

The numerical simulation of radiation propagation in a multichannel fibre amplifier showed that the phases of input beams having the initial spread are equalised during the propagation of these beams due to the spatial filtration of the field by the structure of amplifying channels. The nonlinear part of the refractive index affects the phase matching process to a lesser extent. An increase in the coupling between the channels enhances the self-organisation of the beams.