Bifurcation analysis of laser autosolitons

An investigation is reported of one-dimensional stationary localised radiation structures (‘laser autosolitons’), which appear in a wide-aperture laser with a saturable absorber under conditions of hard lasing excitation. Bifurcation theory methods are used to find the range of existence of single autosolitons and of their coupled states. It is shown that such structures correspond to a transverse dependence of the field amplitude which is either symmetric and node-free or antisymmetric and has a single node. An infinite set of single autosolitons with various widths and transverse amplitude profiles is predicted. It is shown that there is an infinite set of ‘two-soliton’ structures differing in respect of the distance between the component autosolitons.