Novel soliton states and bifurcation phenomena in nonlinear fiber couplers

We find and analyze analytically and numerically two new families of coupled soliton states in nonlinear fiber couplers. The bifurcation diagram for the new types of soliton states is constructed. It is shown that the bifurcation diagram for the fiber coupler is similar to the bifurcation diagram for the stationary waves in a symmetric nonlinear planar waveguide. Physical reasons for this analogy are discussed.