Localized waves in the nonlinear rhombic waveguide array

Solitary electromagnetic waves propagating along the waveguides forming a rhombic one-dimensional lattice are considered. Two waveguides that are part of the unit cell are assumed to be made of an optical linear material, while the third waveguide from the same array is composed of material with the cubic nonlinearity. The equations of the coupled waves spreading in each waveguide are solved under some approximation. These solutions represent the breather like solitary waves, which are akin to three component soliton.