Higher-order harmonics generation based on near-field scattered laser pulse in Au-Si core-shell nanospheres

[Display omitted] •Calculated scattered near-field from the core-shell nanosphere using Mie Theory.•Enhancement of scattered near-field around 800 nm.•Production of higher harmonics via Au-Si core-shell nanosphere.•Increasing the incident intensity beyond the damage threshold of metal core. We present theoretical studies of high-order harmonic generation (HHG) from a hydrogen atom located around metal-insulator core-shell nanosphere using 800 nm Ti: sapphire laser field. Near-fields scattered by a core-shell nanosphere are calculated using the Mie scattering approach. In order to control the scattered field of the Si film coated gold nanoparticles, two parameters (i) the size of core (ii) the shell thickness, which enable to shift the peak of the scattered field to the near infrared region, must be considered. We show that the amplification and inhomogeneity of local fields play an important role in the HHG cut off increment.