We report a rich spectrum of isolated solitons residing inside (embedded into) the continuous radiation spectrum in a simple model of three-wave spatial interaction in a second-harmonic-generating planar optical waveguide equipped with a quasi-one-dimensional Bragg grating. An infinite sequence of fundamental embedded solitons are found, which differ by the number of internal oscillations. Branches of these zero-walkoff spatial solitons give rise, through bifurcations, to several secondary branches of finite-walkoff solitons. The structure of the bifurcating branches suggests a multistable configuration of spatial optical solitons, which may find applications in photonics.
|Publication status||Published - 1999|