Nonsymmetrical spatial soliton formation in the system of two nonlinear thin films

Summary form only given. Studying of soliton like structures in nonlinear optical systems gain an importance in the recent years due to the possibility of its applications in optical devices of information processing and storage. Apart from this the general interest attract structures that appear in multicomponent systems. Different components can nonlinearly interact, that leads to the arising of nontrivial spatial solitons. We theoretically investigate a system, comprising of two thin layers (with thickness less than the incident light wavelength) with a resonant nonlinearity. Layers are separated by a linear medium and irradiated from both sides by a monochromatic and spatially homogeneous light wave. It is obvious that in the case of equal incident fields, there is a symmetrical solution where all variables in both films are equal. We have shown that with increasing incident fields (symmetrical from both sides) pitchfork symmetry-breaking bifurcation takes place above some threshold. Taking into account transverse spatial perturbations we have found pattern-forming instabilities on the symmetrical and nonsymmetrical branches. We concentrate on the symmetrical branch near the pitchfork symmetry-breaking bifurcation.