Nonlinear light generation at the high energy range of a 3D opal film

In the present paper, we experimentally show that SHG is also possible in a NL artificial opal, at the high energy range, where the system displays a truly 3D behavior. We have fabricated a nonlinear opal film of monodisperse polystyrene spheres coated with a dye nonlinear molecule. We have measured the SH forward-generated transmitted light upon incidence of a frequency field, propagating close to direction of the photonic crystal. we show that the group velocity slowing-down at the high energy range of 3D photonic nanostructures provides an enhancement mechanism for the nonlinear process.