Spontaneous symmetry breaking of nonlinear states in optical cavities with radiative losses

The dynamics of one-dimensional periodically modulated optical cavities are studied in the framework of coupled counterpropagating wave approximation. It is shown that in these systems, a spontaneous symmetry breaking bifurcation can occur, resulting in the formation of the dynamically stable asymmetric states with nonzero energy flux. Bright cavity solitons nestling on the spatially uniform backgrounds with broken symmetry are found and investigated in detail. One of the distinguishing features of the solitons on the asymmetric background is that they can exist at the pump powers much less than those needed for the formation of the solitons on the symmetric backgrounds.