We construct a family of bright optical solitons composed fundamental-frequency (FF) and second-harmonic (SH) components in the one-dimensional (planar) waveguide with quadratic (second-harmonic-generating) nonlinearity effective fractional diffraction, characterized by Lévy index α, taking values between 2 0.5, which correspond to non-fractional diffraction critical collapse, respectively. The...

We employ transformation optics to optimize the generic nonlinear wave interaction of second-harmonic generation (SHG) from a pair touching metallic wires. demonstrate six orders magnitude increase in efficiency with respect SHG single wire, and ten scattered power by increasing background permittivity. These results have clear implications for design nanostructured frequency-conversion devices...