Three-wave mixing of dipole solitons in one-dimensional quasi-phase-matched nonlinear crystals

Abstract

In this paper, a quasi-phase-matched (QPM) technique is introduced for soliton transmission in a quadratic (x (2)) nonlinear crystal to realize stable transmission of dipole solitons in one-dimensional (1D) space under three-wave mixing. We report four types of solitons as dipole solitons with distances between their bimodal peaks that can be laid out in different stripes. We study three cases of these solitons: spaced three stripes apart, one stripe apart, and confined to the same stripe. For the case of three stripes apart, all four types have stable results, but for the case of one stripe apart, stable solutions can only be found at w 1 = w 2, and for the condition of dipole solitons confined to one stripe, stable solutions exist only for Type1 and Type3 at w 1 = w 2. The stability of the soliton solution is solved and verified using the imaginary time propagation (ITP) method and real-time transfer propagation (RTP), and soliton solutions are shown to exist in the multistability case. In addition, the relations of the transportation characteristics of the dipole soliton and the modulation parameters are numerically investigated. Finally, possible approaches for experimental realization of the solitons are outlined.