Parametric localized modes in quadratic nonlinear photonic structures

Sukhorukov, Andrey A.; Kivshar, Yuri S.; Bang, Ole; Soukoulis, Costas M.

Parametric localized modes in quadratic nonlinear photonic structures

Authors

Sukhorukov, Andrey A.

Kivshar, Yuri S.

Bang, Ole

Soukoulis, Costas M.

Description

We analyze two-color spatially localized modes formed by parametrically coupled fundamental and second-harmonic fields excited at quadratic (or chi-2) nonlinear interfaces embedded into a linear layered structure --- a quasi-one-dimensional quadratic nonlinear photonic crystal. For a periodic lattice of nonlinear interfaces, we derive an effective discrete model for the amplitudes of the fundamental and second-harmonic waves at the interfaces (the so-called discrete chi-2 equations), and find, numerically and analytically, the spatially localized solutions --- discrete gap solitons. For a single nonlinear interface in a linear superlattice, we study the properties of two-color localized modes, and describe both similarities and differences with quadratic solitons in homogeneous media.
9 pages, 8 figures