Scattering-assisted second harmonic generation of structured fundamental wave.

We study a scattering-assisted second harmonic generation process of a structured fundamental wave, whose phase front is periodically modulated, in a homogenous nonlinear medium. Scattering-assisted multiple-conical second harmonic in a one-dimensional structured fundamental wave and second harmonic belts in two-dimensional cases were observed. The experimental results are consistent with our analysis. This method not only allows dynamic control of the scattering-assisted second harmonic signal, but also has potential applications in various nonlinear frequency conversion processes.