Control of the number of solitons in a fibre laser by resonant injection of external narrow-band light

We study mechanisms underlying the processes of production and annihilation of soliton pulses under the action of external injection. It is shown that, depending on the current pump power of a fibre soliton laser, injection can stimulate the creation of a new soliton by acting on the continuous background in the cavity, or lead to soliton annihilation, reducing the saturable gain. The results of the numerical simulation are in fundamental agreement with the experimental results.